Daylight collectors with thermal control

ABSTRACT

Lighting devices and methods for providing daylight to the interior of a structure are disclosed. Some embodiments disclosed herein provide a daylighting device including a tube having a sidewall with a reflective interior surface, a light collecting assembly, and a light reflector positioned to reflect daylight into the light collector. In some embodiments, the light collector is associated with one or more light-turning and/or light reflecting structures configured to increase the amount of light captured by the daylighting device. Optical elements may allow for the absorption and/or selective transmission of infrared light away from an interior of the daylighting device.

INCORPORATION BY REFERENCE TO PRIORITY APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/710,894, filed Dec. 11, 2012, titled DAYLIGHT COLLECTORS WITH THERMALCONTROL. The entire contents of the above-identified application isincorporated by reference herein for all purposes and made part of thisspecification.

BACKGROUND Field

This disclosure relates generally to daylighting and to light collectorsused in daylighting systems.

Description of Related Art

Daylighting systems typically include windows, openings, and/or surfacesthat provide natural light to the interior of a building. Examples ofdaylighting systems include skylights and tubular daylighting deviceinstallations. Various devices and methods exist for receiving daylightinto a daylighting device. Certain currently known devices and methodsfor receiving daylight into a daylighting device suffer from variousdrawbacks.

SUMMARY

Lighting devices and methods for providing daylight to the interior of astructure are disclosed. Some embodiments disclosed herein provide adaylighting device including a tube having a sidewall with a reflectiveinterior surface, a light collecting assembly, and a light reflectorpositioned to reflect daylight into the light collector. In someembodiments, the light collector is associated with one or morerefractive and/or reflective elements configured to increase the amountof light captured by the daylighting device.

Some embodiments provide an at least partially transparentlight-collecting device for directing daylight into a collector baseaperture. The device can include a top cover portion and a substantiallyvertical sidewall portion configured to support the top cover portionabove an upper end of the substantially vertical sidewall portion and todefine a collector base aperture at a lower end of the substantiallyvertical sidewall portion. In certain embodiments, the substantiallyvertical portion has a height that extends between the top cover portionand the collector base aperture, and is configured to receive daylight.

The light-collecting device can include a prismatic element associatedwith the substantially vertical sidewall portion and configured to turnat least a portion of daylight received by the vertical portion towardsthe collector base aperture, and a reflector associated with thesubstantially vertical portion configured to reflect the portion ofdaylight towards the opening. In certain embodiments, the collector baseaperture has a width and is configured to be positioned adjacent to anopening of a building when the light-collecting device is installed aspart of a tubular daylighting device installation.

Certain embodiments disclosed herein provide an at least partiallytransparent light-collecting device configured to direct daylightthrough a collector base aperture and into an interior of a buildingwhen the light-collecting device can be installed on a roof of thebuilding. The device can include a top cover portion and a substantiallyvertical sidewall portion configured to support the top cover portionabove an upper end of the substantially vertical sidewall portion and todefine a collector base aperture at a lower end of the substantiallyvertical sidewall portion, wherein the substantially vertical portionhas a height that extends between the top cover portion and thecollector base aperture, and wherein the substantially vertical portioncan be configured to receive a substantial amount of daylight duringmidday hours. The device can include a prismatic element associated withthe substantially vertical sidewall portion and configured to turn atleast a portion of daylight received by the vertical portion towards thecollector base aperture, as well as an infrared control elementassociated with the substantially vertical sidewall portion configuredto absorb or transmit at least a portion of infrared (IR) light of theportion of daylight. The light-collecting device can be configured to bepositioned over an opening in a roof of a building and can be configuredto direct daylight into the opening in the roof when thelight-collecting device is installed as part of a daylighting deviceinstallation.

The infrared control element can be configured to absorb the at least aportion of infrared light and reradiate the portion of infrared lightaway from an interior of the light-collecting device. The infraredcontrol element can include a material having high emissivitycharacteristics, such as a material having an emissivity value ofgreater than 0.90. In certain embodiments, the sidewall portion can beconfigured to absorb the reradiated portion of infrared light. Thesidewall portion can be configured to transmit the reradiated portion ofinfrared light. For example, the sidewall portion can include acrylic.

In certain embodiments, the infrared control element can be at leastpartially secured to the sidewall portion by an adhesive configured toabsorb infrared light incident on a surface of the infrared controlelement. The height of the vertical portion can be greater than thewidth of the collector base aperture. In certain embodiments, the topcover portion can be substantially flat. In other embodiments, the topcover portion includes a dome-shaped or cone-shaped surface.

The vertical portion can include a plurality of vertically-arrangedsegments, including a top segment, a middle segment, and a bottomsegment. The top, middle, and bottom segments can be each approximately5 to 10 inches in height. In certain embodiments, the top, middle, andbottom segments can be each a uniform height.

The infrared control element can be at least partially transparent withrespect to infrared light. In certain embodiments, the vertical portionis substantially cylindrically shaped. In such embodiments, the infraredcontrol element can be curved and nestingly disposed along an interiorsurface of the vertical portion. The vertical portion can include afirst semi-circle portion that is at least partially transparent, and asecond semi-circle portion that is at least partially reflective. Forexample, the second semi-circle portion can be configured to absorb asubstantial portion of infrared light incident on a surface of thesecond semi-circle portion. In certain embodiments, the secondsemi-circle portion includes a surface in thermal communication with ahigh-emissivity material configured to facilitate radiation of heat awayfrom the second semi-circle portion, such paint having an emissivityvalue greater than or equal to about 0.9. In certain embodiments, thevertical portion can be integrated with an internally reflective tubeconfigured to channel light towards an interior space of the building.

Certain embodiments disclosed herein provide a process of illuminatingan interior of a building. The process can include receiving daylight ona substantially vertical surface, turning the daylight towards anopening in a building using a prismatic element disposed within alight-collecting device, and transmitting or radiating a portion ofinfrared light of the daylight out of the light-collecting device.

The process can include radiating the portion of infrared light out ofthe light-collecting device at least partially by absorbing the portionof infrared light with an adhesive material and reradiating the portionof infrared light using the adhesive material and/or material havinghigh emissivity characteristics.

Certain embodiments provide a process of manufacturing an at leastpartially transparent light-collecting device for directing daylightinto a building interior. The process can include providing a lightcollecting device configured to receive daylight on a substantiallyvertical surface when installed on a building having an opening,disposing a prismatic element within the light collecting device, anddisposing an infrared control element adjacent to a wall of the lightcollecting device. The prismatic element can be configured to turn atleast a portion of daylight received on the substantially verticalsurface towards the opening. The infrared control element can beconfigured to transmit or absorb infrared light of the portion ofdaylight.

Certain embodiments disclosed herein provide an at least partiallytransparent light-collecting device configured to direct daylightthrough a collector base aperture and into an interior of a buildingwhen the light-collecting device can be installed on a roof of thebuilding. The light-collecting device can include a top cover portionand a substantially vertical sidewall portion configured to support thetop cover portion above an upper end of the substantially verticalsidewall portion and to define a collector base aperture at a lower endof the substantially vertical sidewall portion, wherein thesubstantially vertical portion has a height that extends between the topcover portion and the collector base aperture, and wherein thesubstantially vertical portion can be configured to receive asubstantial amount of daylight during midday hours. The light-collectingdevice can include a prismatic element associated with the substantiallyvertical sidewall portion and configured to turn at least a portion ofdaylight received by the vertical portion towards the collector baseaperture and a reflector associated with the substantially verticalsidewall portion configured to reflect at least a portion of visiblelight of the portion of daylight towards the opening and absorb ortransmit at least a portion of infrared (IR) light of the portion ofdaylight. In certain embodiments, the light-collecting device isconfigured to be positioned over an opening in a roof of a building andcan be configured to direct daylight into the opening in the roof whenthe light-collecting device can be installed as part of a daylightingdevice installation.

The reflector can be configured to absorb the at least a portion ofinfrared light and reradiate the portion of infrared light away from aninterior of the light-collecting device. The reflector can include amaterial having high emissivity characteristics, such as a materialhaving an emissivity value of greater than 0.90. The sidewall portioncan be configured to absorb the reradiated portion of infrared light.The sidewall portion can be configured to transmit the reradiatedportion of infrared light. For example, the sidewall portion can includeacrylic.

In certain embodiments, the reflector is at least partially secured tothe sidewall portion by an adhesive configured to absorb infrared lightincident on a surface of the reflector. The height of the verticalportion can be greater than the width of the collector base aperture.The vertical portion can include a plurality of vertically-arrangedsegments, including a top segment, a middle segment, and a bottomsegment. For example, the top, middle, and bottom segments can be eachapproximately 5 to 10 inches in height. In certain embodiments, the top,middle, and bottom segments can be each a uniform height. The reflectorcan be associated with the top segment and the middle segment. In someembodiments, the reflector is not associated with and/or does not extendto the bottom segment. The reflector can be at least partiallytransparent with respect to infrared light and/or other wavelengths ofradiation that do not contribute to desired illumination of a building.

The vertical portion can be substantially cylindrically shaped.Furthermore, the reflector can be curved and nestingly disposed along aninterior surface of the vertical portion. In certain embodiments, thevertical portion includes a first semi-circle portion that can be atleast partially transparent, and a second semi-circle portion that canbe at least partially reflective. For example, the second semi-circleportion can be configured to absorb a substantial portion of infraredlight incident on a surface of the second semi-circle portion. Thesecond semi-circle portion can include a surface in thermalcommunication with a high-emissivity material configured to facilitateradiation of heat away from the second semi-circle portion, such asmaterial including paint with an emissivity value greater than or equalto about 0.9. In certain embodiments, the vertical portion is integratedwith an internally reflective tube configured to channel light towardsan interior space of the building.

Certain embodiments disclosed herein provide a process of illuminatingan interior of a building. The process can include receiving daylight ona substantially vertical surface, turning the daylight towards anopening in a building using a prismatic element disposed within alight-collecting device, reflecting a portion of visible light of thedaylight towards the opening using a reflector, and transmitting orradiating a portion of infrared light of the daylight out of thelight-collecting device. The process can include radiating the portionof infrared light out of the light-collecting device at least partiallyby absorbing the portion of infrared light with an adhesive material andreradiating the portion of infrared light using the adhesive material,such as by using material having high emissivity characteristics.

Certain embodiments provide a process of manufacturing an at leastpartially transparent light-collecting device for directing daylightinto a building interior. The process can include providing a lightcollecting device configured to receive daylight on a substantiallyvertical surface when installed on a building having an opening,disposing a prismatic element within the light collecting device, anddisposing a reflector adjacent to a wall of the light collecting device.The prismatic element can be configured to turn at least a portion ofdaylight received on the substantially vertical surface towards theopening. In addition, the reflector can be configured to reflect visiblelight of the portion of daylight towards the opening, and transmit orabsorb infrared light of the portion of daylight.

Certain embodiments disclosed herein provide an at least partiallytransparent light-collecting device configured to direct daylightthrough a collector base aperture and into an interior of a buildingwhen the light-collecting device can be installed on a roof of thebuilding. The device can include a top cover portion and a substantiallyvertical sidewall portion configured to support the top cover portionabove an upper end of the substantially vertical sidewall portion and todefine a collector base aperture at a lower end of the substantiallyvertical sidewall portion, wherein the substantially vertical portionhas a height that extends between the top cover portion and thecollector base aperture, and wherein the height of the substantiallyvertical portion can be greater than a width of the collector baseaperture. The device can include a prismatic element configured to turna portion of light that passes through the top cover portion orsubstantially vertical sidewall portion. The light-collecting device canbe configured to be positioned over an opening in a roof of a buildingand can be configured to direct daylight into the opening in the roofwhen the light-collecting device is installed as part of a daylightingdevice installation.

The device can include a reflector associated with the substantiallyvertical portion configured to reflect the portion of daylight towardsthe opening. The collector base aperture can be substantially circularin shape, and the width can be equal to a diameter of the collector baseaperture. In certain embodiments, an aspect ratio of the height of thevertical portion to the width of the collector base aperture is greaterthan 1.2 to 1. For example, the aspect ratio can be greater than 1.5 to1, 1.7 to 1, 2 to 1, or greater. In certain embodiments, the aspectratio is in the range of 1.2-1.5 to 1, 1.5-1.75 to 1, or 1.75-2.0 to 1.

The top cover portion can be substantially flat, or can be at leastpartially dome, or cone-shaped. The vertical portion can include aplurality of vertically-arranged segments, including a top segment, amiddle segment, and a bottom segment. In some embodiments, the topsegment is associated with first optical elements having firstlight-turning characteristics and the middle portion is associated withsecond optical elements having second light-turning characteristics. Insome embodiments, light transmitting through the bottom segment is notrefracted by light-turning optical elements. In certain embodiments,each of the top, middle, and bottom segments has a height that isgreater than or equal to about 5 inches and/or less than or equal toabout 10 inches. The top, middle, and bottom segments can each begreater than 10 inches in height. For example, the top, middle, andbottom segments can be each approximately 10 to 18 inches in height. Incertain embodiments, the top, middle, and bottom segments are each ofuniform height.

In certain embodiments, the vertical portion is substantiallycylindrically shaped. The vertical portion can be integrated with aninternally reflective tube configured to channel light towards aninterior space of the building. The height of the vertical portion canbe between 18 and 35 inches, or between 35 and 45 inches. In certainembodiments, the width of the collector base aperture is between 8 and16 inches, or between 16 and 20 inches, or between 20 and 25 inches.

Certain embodiments disclosed herein provide an at least partiallytransparent light-collecting device for directing daylight into abuilding interior. The light-collecting device can include a top coverportion, a base aperture having a width and configured to be disposedadjacent to an opening of a building, and a substantially verticalportion having a height, the vertical portion extending between the topportion and the base aperture and configured to receive daylight wheninstalled on a building. The light-collecting device can include areflector associated with the vertical portion, the reflector configuredto reflect at least a portion of daylight received by the verticalportion towards the opening. The vertical portion can be associated witha prismatic element configured to turn the portion of daylight receivedby the vertical portion towards the opening. Furthermore, the height ofthe vertical portion can be greater than the width of the opening of thebuilding.

The vertical portion can have a rectangular cross-sectional shape, asubstantially elliptical cross-sectional shape, or any other desiredcross-sectional shape. The vertical portion can be constructed out of asingle planar sheet formed in the shape of an ellipse, wherein two endsof the sheet can be joined to form a singular vertical seam.Alternatively, the vertical portion can include a plurality ofhorizontally-arranged curved sheets that can be configured to be joinedtogether to form an ellipse. In certain embodiments, the verticalportion has a substantially triangular cross-sectional shape.

Certain embodiments disclosed herein provide a process of illuminatingan interior of a building. The process can include receiving daylight ona substantially vertical surface, turning the daylight towards anaperture lying in a substantially horizontal plane using a prismaticelement disposed within a light-collecting device, and reflecting thedaylight towards the opening using a reflector. The substantiallyvertical surface may a height greater than a width of the aperture.

Certain embodiments disclosed herein provide a process of manufacturingan at least partially transparent light-collecting device for directingdaylight into a building interior. The process can include providing alight collecting device configured to receive daylight on asubstantially vertical surface when installed on a building having anopening and disposing a reflector adjacent to a wall of the lightcollecting device. The reflector can be configured to reflect theportion of daylight towards the opening through a base aperture of thelight collecting device, the substantially vertical surface having aheight that can be greater than a width of the base aperture.

Certain embodiments disclosed herein provide a passive light-collectingdevice for directing sunlight into a building interior. Thelight-collecting device can include a top cover portion, a base aperturehaving a width and configured to be disposed adjacent to an opening of abuilding, and a substantially vertical portion having a height thatextends between the top portion and the base aperture and can beconfigured to receive sunlight. The light-collecting device can beconfigured to direct a first luminous flux through the base aperturewhen the light-collecting device is exposed to sunlight at a solaraltitude of approximately 30 degrees, and to direct a second luminousflux through the base aperture when the light-collecting device isexposed to sunlight at a solar altitude of approximately 70 degrees,wherein the first luminous flux is greater than or equal to about 75% ofthe second luminous flux when the light-collecting device is exposed tosubstantially only direct sunlight on a clear day.

The light-collecting device can include a prismatic element associatedwith the vertical portion and configured to turn at least a portion ofsunlight received by the vertical portion towards the base aperture. Thelight-collecting device can include a reflector associated with thevertical portion configured to reflect the portion of sunlight towardsthe base aperture. In certain embodiments, the height of the verticalportion can be greater than the width of the base aperture.

In certain embodiments, the top cover portion is substantially flat. Thetop cover portion can include a dome-shaped surface, a cone-shapedsurface, a planar surface, a faceted surface, another surface shape, ora combination of surface shapes. The top cover can be associated with asecond prismatic element configured to turn sunlight incident on the topcover towards the base aperture. The second luminous flux can be greaterthan 18,000 lumens.

In certain embodiments, the vertical portion is substantiallycylindrically shaped. The vertical portion can include a plurality ofvertically-arranged segments, including a top segment, a middle segment,and a bottom segment. For example, the top segment can be associatedwith a first prismatic element having first light-turningcharacteristics and the middle portion can be associated with a secondprismatic element having second light-turning characteristics. Thebottom segment may not be associated with light-turning opticalelements. The top, middle, and bottom segments can be each approximately5 to 10 inches in height, and may each be of uniform height.

The vertical portion can be integrated with an internally reflectivetube configured to channel light towards an interior space of thebuilding. The height of the vertical portion can be between 20 and 25inches, or between 35 and 45 inches. In certain embodiments, thereflector is disposed adjacent to an interior surface of thesubstantially vertical portion. Alternatively, the reflector can bedisposed adjacent to an outer surface of the substantially verticalportion.

Certain embodiments disclosed herein provide a passive light-collectingdevice for directing sunlight into a building interior. Thelight-collecting device can include a top cover portion, a base aperturehaving a width and configured to be disposed adjacent to an opening of abuilding, and a substantially vertical portion having a height thatextends between the top portion and the base aperture and can beconfigured to receive sunlight. The light-collecting device can beconfigured to direct a first luminous flux through the base aperturewhen the light-collecting device is exposed to sunlight at a solarazimuth of approximately 45 degrees and a first solar altitude, anddirect a second luminous flux through the base aperture when thelight-collecting device can be exposed to sunlight at a solar azimuth ofapproximately 0 degrees, wherein the first luminous flux can be greaterthan or equal to about 75% of the second luminous flux when thelight-collecting device can be exposed to substantially only directsunlight on a clear day.

The light-collecting device can include a prismatic element associatedwith the vertical portion and configured to turn at least a portion ofsunlight received by the vertical portion towards the base aperture. Thelight-collecting device can include a reflector associated with thevertical portion configured to reflect the portion of sunlight towardsthe base aperture. In certain embodiments, the second luminous flux canbe greater than 18,000 lumens.

Certain embodiments disclosed herein provide an at least partiallytransparent light-collecting device for directing sunlight into abuilding interior. The light-collecting device can include a top coverportion, a base aperture having a width and configured to be disposedadjacent to an opening of a building, and a substantially verticalportion having a height that extends between the top portion and thebase aperture and can be configured to receive sunlight. Thelight-collecting device can be configured to direct a first luminousflux through the base aperture when the light-collecting device can beexposed to sunlight at a solar altitude of approximately 30 degrees anda solar azimuth of approximately 45 degrees, and direct a second amountof light through the base aperture when exposed to sunlight at a solaraltitude of approximately 70 degrees and a solar azimuth ofapproximately 0 degrees, wherein the first luminous flux can be greaterthan or equal to about 75% of the second luminous flux when thelight-collecting device can be exposed to substantially only directsunlight on a clear day.

The light-collecting device can include a prismatic element configuredto turn at least a first portion of sunlight received by the verticalportion towards the base aperture. The light-collecting device caninclude a reflector associated with the vertical portion, the reflectorconfigured to reflect at least a second portion of the sunlight receivedby the vertical portion towards the base aperture.

In certain embodiments, the top cover can be associated with a secondprismatic element configured to turn sunlight incident on the top covertowards the base aperture, and can be substantially flat. The verticalportion may have a substantially rectangular, elliptical, triangular,hexagonal, pentagonal, or octagonal cross-sectional shape.

Certain embodiments disclosed herein provide a process of illuminatingan interior of a building. The process can include receiving firstsunlight having a solar altitude of approximately 30 degrees on avertical surface, directing the first sunlight into an opening in abuilding, receiving second sunlight having a solar altitude ofapproximately 70 degrees on the vertical surface, and directing thesecond sunlight into the opening in the building. The first sunlight andthe second sunlight can include direct sunlight, and the first sunlightcan include a luminous flux that is greater than or equal to about 75%of a luminous flux of the second sunlight when said receiving the firstsunlight and receiving the second sunlight are performed on a clear day.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments are depicted in the accompanying drawings forillustrative purposes, and should in no way be interpreted as limitingthe scope of the inventions. In addition, various features of differentdisclosed embodiments can be combined to form additional embodiments,which are part of this disclosure. Any feature or structure can beremoved or omitted. Throughout the drawings, reference numbers can bereused to indicate correspondence between reference elements.

FIG. 1 illustrates a block diagram representing an embodiment of adaylighting device.

FIG. 2 illustrates a cutaway view of an example of a daylighting deviceinstalled in a building for illuminating an interior room of thebuilding.

FIG. 3 illustrates a cutaway view of an example of a daylighting deviceinstalled in a building for illuminating an interior room of thebuilding.

FIG. 4 illustrates a cutaway view of an example of a daylighting deviceinstalled in a building.

FIG. 5 illustrates an embodiment of a daylighting device incorporating acollimator at a terminal portion of the daylighting device.

FIG. 6 illustrates an embodiment of the light collector shown in FIG. 1.

FIG. 7 illustrates an embodiment of a daylighting device including alight collector with a dome-shaped top portion.

FIG. 8 illustrates an embodiment of a daylighting device with a topportion having a triangular cross-section.

FIGS. 9A-9F illustrate embodiments of light collectors having variouscross-sectional shapes.

FIG. 10 illustrates a cross-sectional view of a light collectorincluding both a side portion, and a top portion.

FIG. 11 illustrates a cross-sectional view of a portion of the prismaticelement shown in FIG. 10.

FIG. 12 illustrates a cross-sectional view of a light collectorincluding a side portion that includes a plurality of verticallyarranged optical zones.

FIG. 13 is a graph showing reflectivity profiles of two differentreflective materials.

FIG. 14A illustrates a perspective view of an embodiment of a lightreflector for disposing within, adjacent to, or in integration with, alight collecting assembly.

FIG. 14B, illustrates a top view of an embodiment of the reflector shownin FIG. 14A

FIG. 14C illustrates a cross-sectional view of a vertically-orientedplanar reflector.

FIG. 15 illustrates a perspective view of an embodiment of daylightingdevice including a light collector incorporating a reflector.

FIG. 16 illustrates a perspective view of an embodiment of daylightingdevice including a light collector incorporating a reflector.

FIG. 17A illustrates an embodiment of a light collector having atransparent portion and a reflector assembly.

FIG. 17B illustrates a top view of an embodiment of a connectingstructure of a light collector.

FIG. 18 illustrates an embodiment of a light collector having areflector assembly with a high-emissivity coating.

FIG. 19 illustrates an embodiment of a daylighting device including alight collector having prismatic and reflective optical elements.

FIG. 20 illustrates a perspective view of an embodiment of a lightcollector.

FIG. 21A illustrates an embodiment of a light collector formed from asingular panel.

FIG. 21B illustrates a top view of an embodiment of a portion of a lightcollector having a circumference that includes multiple curved panels.

FIG. 22 illustrates a packaging configuration for an embodiment of oneor more curved light collector panels.

FIG. 23 illustrates a packaging configuration for an embodiment of oneor more curved light collector panels.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

Although certain embodiments and examples are disclosed herein,inventive subject matter extends beyond the examples in the specificallydisclosed embodiments to other alternative embodiments and/or uses, andto modifications and equivalents thereof. Thus, the scope of the claimsappended hereto is not limited by any of the particular embodimentsdescribed below. For example, in any method or process disclosed herein,the acts or operations of the method or process can be performed in anysuitable sequence and are not necessarily limited to any particulardisclosed sequence. Various operations can be described as multiplediscrete operations in a manner or order that can be helpful inunderstanding certain embodiments; however, the order of descriptionshould not be construed to imply that these operations areorder-dependent. Additionally, the structures, systems, and/or devicesdescribed herein can be embodied as integrated components or as separatecomponents. For purposes of comparing various embodiments, certainaspects and advantages of these embodiments are described. Notnecessarily all such aspects or advantages are achieved by anyparticular embodiment. Thus, for example, various embodiments can becarried out in a manner that achieves or optimizes one advantage orgroup of advantages as taught herein without necessarily achieving otheraspects or advantages as can be taught or suggested herein.

FIG. 1 depicts a block diagram representing an embodiment of adaylighting device 100. The daylighting device 100 can be a passivelight-collection and distribution system for providing daylight to aninterior of a building or other structure. The daylighting device 100includes a light collector 110 which is exposed, either directly orindirectly to a source of light, such as, for example, the Sun. Lightenters the light collector and propagates into a tube 120. For example,the light may enter the light collector 110 through a substantiallyvertical daylight-collection surface and/or top cover portion of thelight collector. The tube 120 provides a channel, or pathway, betweenthe light collector 110 and a light-aligning structure 130. The interiorsurface of the tube 120 is at least partially reflective. In someembodiments, at least a portion of the interior surface of the tube 120is specularly reflective.

As used herein, the terms “substantially vertical” and “vertical” areused in their broad and ordinary sense and include, for example,surfaces that are generally perpendicular to the ground, surfaces thatare generally perpendicular to a horizontal plane, and/or surfaces thatdeviate by less than about 10° from a plane perpendicular to the groundand/or a horizontal plane. Such surfaces can be planar, curved, orirregularly shaped while still being substantially vertical so long asan elongate dimension of a surface is generally vertical. The terms“substantially horizontal” and “horizontal” are used in their broad andordinary sense and include, for example, surfaces that are generallyparallel to the ground, surfaces that are generally parallel to the roofof a building, and/or surfaces that deviate by less than or equal toabout 10° from a plane parallel to the ground and/or a roof. Suchsurfaces can be planar, curved, or irregularly shaped while still beingsubstantially horizontal so long as an elongate dimension of a surfaceis generally horizontal.

The light collector permits exterior light, such as natural light, toenter the interior of the reflective tube 120. The light collector 110can have one or more components. For example, the light collector 110can include a transparent dome, a prismatic dome, other prismaticelements, one or more light turning structures or elements, a durablecover, one or more reflective surfaces (e.g., positioned inside oroutside of a portion of the collector 110), other optical elements,other components, or a combination of components. At least somecomponents of the light collector can be configured to be positioned onthe roof 102 of the building or in another suitable area outside thebuilding. The light collector 110 can include a transparent coverinstalled on the roof 102 of the building or in another suitablelocation. The transparent cover can be cylindrically shaped,dome-shaped, or can include any other suitable shape or combination ofshapes, and can be configured to capture sunlight during certain periodsof the day. In certain embodiments, the cover keeps environmentalmoisture and other material from entering the tube. The cover can allowexterior light, such as daylight, to enter the system.

In the example embodiments disclosed, the measure h_(c) represents aheight of a substantially vertical sidewall portion of the lightcollector 110. In certain embodiments, the sidewall portion presents asubstantially vertical daylight-collection surface through whichdaylight may enter the daylighting device 100. The measure we representsa width of a portion of the collector, such as the width of the base ortop portions of the collector 110. In certain embodiments, the width ofthe collector is substantially uniform over its height h_(c). The widthw_(c) of the collector at its base can be greater than the width of thetube 120 at a point near the collector base. In some embodiments, adaylight device is configured such that a width of the tube into whichdaylight is directed, at least in a region disposed in proximity to thecollector base, is less than the height h_(c) of the collector. Thewidth of the tube w_(t) may represent a width of a target area to whichthe light collector 110 is configured to direct daylight entering thecollector. The term “target area” is used herein according to its broadand ordinary meaning and can be used to refer to an area through which adaylight collector is configured to direct daylight in order for thedaylight to enter an internally-reflective tube between a roof structureand interior room of a building.

The relationship between the height of the collector and the width ofthe tube or width of the target area of the collector can becharacterized using a ratio between the quantities that will be referredto herein as the aspect ratio. In general, the aspect ratio refers tothe ratio between the height of the collector and the width of the tubewith which the collector is configured to be used. For example, in someembodiments, the height h_(c) of the collector, as compared to the widthw_(t) of the tube/target area 120, or width w_(c) of the collector 110,can have an aspect ratio of approximately 1.2 to 1, or greater. The term“collector” is used herein according to its broad and ordinary meaningand includes, for example, a cover, window, or other component orcollection of components, configured to direct daylight into an openingof a building. A collector can include optical elements that refractand/or reflect daylight such that the luminous flux of natural lightentering a building is greater than if an opening in the buildingincluded a fenestration apparatus without optical elements.

In some embodiments, the cover includes a light collection systemconfigured to enhance or increase the daylight entering the tube 120.The collector 110 can include one or more optical elements, eitherintegrated or non-integrated with respect to the cover, configured toturn light entering one or more portions of the collector 110 generallyin the direction of the tube 120, or opening in the building. The lightcollector 110 can include a top cover. For example, the top cover can beclear or include prisms for refracting daylight toward the collectorbase aperture. The prisms can be fabricated into the cover material orcan be formed in a separate prismatic element placed beneath or above aclear dome. As used herein, prismatic element is used in its broad andordinary sense and includes, for example, prismatic films, moldedprismatic assemblies, extruded prismatic materials, another prismaticmaterial, or a combination of materials.

The daylighting device 100 can be configured such that light enters thecollector 110 and proceeds through the tube 120, which can be internallyreflective, thereby allowing light to propagate through the tube to atargeted area of the building. An auxiliary lighting system (not shown)can be installed in the daylighting device 100 to provide light from thetube to the targeted area when daylight is not available in sufficientquantity to provide a desired level of interior lighting.

The collimator 130 can be configured such that light that wouldotherwise enter the diffuser at undesirable angles is turned to a moredesirable angle. For example, the collimator 130 can ensure that lightpassing through the daylighting device will exit the daylighting deviceat an exit angle of less than or equal to about 45 degrees fromvertical, or at a substantially vertical orientation, when the diffuser140 is in a horizontal arrangement. In some embodiments, the collimator130 may ensure that light passing through the daylighting device willexit the daylighting device at an exit angle of less than or equal toabout 45 degrees from a longitudinal axis of the daylighting device or aportion of the daylighting device. In certain embodiments, thecollimator 130 is configured to reduce or prevent light from exiting thedaylighting device 100 at an angle of between about 45 degrees and about60 degrees from vertical. In this manner, the collimator 130 may reduceor eliminate glare and visibility issues that light exiting a lightingfixture between those angles can cause.

The daylighting device 100 includes a light-diffusing structure, ordiffuser 140. The diffuser 140 spreads light from the tube into the roomor area in which it is situated. The diffuser 140 can be configured todistribute or disperse the light generally throughout a room or areainside the building. Various diffuser designs are possible.

When the daylighting device 100 is installed, the tube 120 can bephysically connected to, or disposed in proximity to, the light-aligningstructure, or collimator 130, which is configured to turn lightpropagating through the daylighting device such that, when light exitsthe daylighting device 100 and/or enters a diffuser 140, the light hasincreased alignment characteristics, as compared to a device without acollimator. In some embodiments, a substantial portion of lightpropagating through the daylighting device 100 may propagate within thedaylighting device at relatively low angles of elevation from ahorizontal plane of reference. Such angles of propagation may, in somesituations, cause the light to have undesirable properties when it exitsthe daylighting device. For example, the optical efficiency of adiffuser substantially positioned within a horizontal plane can besubstantially reduced when light is incident on the diffuser at lowangles of elevation from the horizontal plane. As another example, lightthat is incident on a diffuser at low angles of elevation can result inlight exiting the daylighting device at an exit angle of greater than orequal to about 45 degrees from vertical. Light exiting a daylightingdevice at such angles can create glare and visibility issues in the areaor room being illuminated.

Though the embodiment depicted in FIG. 1 is described with reference toone or more features or components, any of the described features orcomponents can be omitted in certain embodiments. Furthermore,additional features or components not described can be included incertain embodiments in accordance with the device shown in FIG. 1.

FIG. 2 shows a cutaway view of an example of a daylighting device 200installed in a building 205 for illuminating, with natural light, aninterior room 207 of the building. The daylighting device 200 can besuited for use in commercial, high-bay applications, such as instructures or buildings having ceilings above twenty feet high. Forexample the distance h₀ between the floor 208 and a ceiling plane 209can be in the range of approximately 20-28 feet. The daylighting device200 can be configured to improve the performance of a light collectionsystem through the use of a light collector 210, wherein the lightcollector 210 incorporates, or is associated with, one or more passiveoptical elements. The daylighting device 200 can be particularlyconfigured for applications that operate within an approximatelysix-hour window during which daylight is most intense. For example,depending on geographical location of the building 202, among possiblyother things, the daylighting device 200 can be configured to capturedesirable amounts of daylight between the hours of 9:00 am and 3:00 pm.

The light collector 210 can be mounted on a roof 202 of the building andmay facilitate the transmission of natural light into a tube 220. Incertain embodiments, the collector 210 is disposed on a pitched roof. Inorder to compensate for the pitch in the roof, the collector 210 can bemounted to the roof 202 using a flashing 204. The flashing can include aflange 204 a that is attached to the roof 202, and a curb 204 b thatrises upwardly from the flange 204 a and is angled as appropriate forthe cant of the roof 202 to engage and hold the collector 210 in agenerally vertically upright orientation. Other orientations are alsopossible. In certain embodiments, at least a portion of the roof 202 issubstantially flat.

The light collector 210 has a height h_(c) and is disposed adjacent to atube opening having a width, or diameter, w_(t). The tube opening mayprovide a target area into which the light collector 210 is configuredto direct daylight. As used herein, the height h_(c) may refer to theheight of a substantially vertical sidewall portion of the collector210, or may refer to the height of the collector 210 including theheight of a cover portion disposed above the vertical portion. Incertain embodiments, the substantially vertical sidewall portion mayprovide a vertical daylight-collection surface for daylight incident oncertain portions of the collector 210. In certain embodiments, theheight h_(c) is approximately 20-26 inches. In other embodiments, theheight h_(c) can be approximately 35-45 inches. In addition, the widthw_(c) of the tube opening can be between 15-30 inches. For example, inan embodiment, the height h_(c) of the collector 210 is approximately 42inches and the width w_(c) of the tube opening is approximately 25inches. The collector 210 may have a width w_(c) slightly greater thanthe width w_(t) of the tube opening such that when the light collectoris disposed above the tube opening, a lip of the collector 210 extendsbeyond the width of the tube opening. For example, the collector 210 mayhave a 1-inch lip around a circumference or perimeter of the tubeopening, such that the width w_(c) of the collector 210 is approximately2 inches greater than the width of the tube opening w_(t). The heighth_(c) of the collector 210 and the width w_(t) of the tube opening canbe configured to obtain a desirable aspect ratio that providessatisfactory performance characteristics. In certain embodiments, theaspect ratio of height h_(c) to width w_(t) is approximately 1.7:1. Insome embodiments, the aspect ratio is greater than or equal to about1.2:1 and/or less than or equal to about 2:1. Such aspect ratios, inconnection with daylighting device features described herein, mayprovide improved daylight capturing characteristics.

The tube 220 can be connected to the flashing 204 and can extend fromabout a level of the roof 202 through a ceiling level 209 of theinterior room 207. The tube 220 can direct light L_(D2) that enters thetube 220 downwardly to a light diffuser 240, which disperses the lightin the room 207. The interior surface of the tube 220 can be reflective.In some embodiments, the tube 220 has at least a section withsubstantially parallel sidewalls (e.g., a generally cylindrical insidesurface). Many other tube shapes and configurations are possible. Thetube 220 can be made of metal, fiber, plastic, other rigid materials, analloy, another appropriate material, or a combination of materials. Forexample, the body of the tube 220 can be constructed from type 1150alloy aluminum. The shape, position, configuration, and materials of thetube 220 can be selected to increase or maximize the portion of daylightL_(D1), L_(D2) or other types of light entering the tube 220 thatpropagates into the room 207.

The tube 220 can terminate at, or be functionally coupled to, a lightdiffuser 240. The light diffuser 240 can include one or more devicesthat spread out or scatter light in a suitable manner across a largerarea than would result without the diffuser 240 or a similar device. Insome embodiments, the diffuser 240 permits most or substantially allvisible light traveling down the tube 220 to propagate into the room207. The diffuser can include one or more lenses, ground glass,holographic diffusers, other diffusive materials, or a combination ofmaterials. The diffuser 240 can be connected to the tube 220, or othercomponent of the daylighting device 200, using any suitable connectiontechnique. In some embodiments, the diffuser 240 is located in the samegeneral plane as a ceiling level 209 of the building, generally parallelto the plane of the ceiling level 209, or near the plane of the ceilinglevel 209. In certain embodiments, the building 205 has an open ceiling,exposing structure associated with the roof 202. For example, certainhigh-bay buildings may have open-ceiling configurations, exposingstructural I-beams and/or the like. In an open ceiling configuration,the diffuser 240 can be disposed adjacent to a ceiling-level plane 209,rather than a physical ceiling structure.

In certain embodiments, the diameter of the diffuser 240 issubstantially equal to the diameter of the tube 220, slightly greaterthan the diameter of the tube 220, slightly less than the diameter ofthe tube 220, or substantially greater than the diameter of the tube220. The diffuser 240 can distribute light incident on it toward a lowersurface below the diffuser (e.g., the floor 208) and, in some roomconfigurations, toward an upper surface of the room 207. In someembodiments, a diffuser 240 provides substantial amounts of both directdiffusion and indirect diffusion. In some embodiments, the diffuser 240reduces the light intensity in one or more regions of the room interior207.

One or more daylighting devices configured according to the embodimentdescribed with respect to FIG. 2 may increase illumination of abuilding, or decrease the number of devices required to achieve adesired amount of light infusion into the building. For example, certainembodiments described herein may improve performance and/or reduce thenumber of required devices by 20-30%.

The daylighting device 200 can be configured to sustain significantphysical stress without substantial structural damage. For example, incertain embodiments, the daylighting device 200 is configured towithstand a drop test, wherein a bag of sand having particularweight/size characteristics is dropped onto the top of the device from aminimum height. To pass such test, the device can be required towithstand the fall test without allowing the bag to fall through theopening in the building. In some embodiments, a daylighting system isconfigured to meet standards and/or regulations promulgated by standardsorganizations and/or government agencies that are designed to improvethe safety of rooftop environments containing daylighting fixtures. Forexample, certain embodiments are configured to meet the FederalOccupational Safety and Health Administration (OSHA) regulations, whichprovide, for example, that skylight screens shall be of suchconstruction and mounting that they are capable of withstanding a loadof at least 200 pounds applied perpendicularly to a surface. Daylightingdevices can be constructed to meet regulatory standards. In certainembodiments, one or more portions of the flashing 204, and/or collector210 can be constructed and/or mounted such that the collector 210 is notdamaged to the extent that an opening or aperture providing an ingressinto the building interior 207 is created therein, when a 267-lb. sandbag, having an approximately 5.5″ bull nose, is dropped generallyperpendicularly to a plane of the roof and/or to a top surface of thecollector 210 from a height of about 36″ above the roof onto the centerof the top portion of the daylight collector.

FIG. 3 shows a cutaway view of an example of a daylighting device 300installed in a building 305 for illuminating, with natural light, aninterior room 307 of the building. The daylighting device 300 includes alight collector 310 mounted on a roof structure 302 of the building 305that allows natural light to enter a tube 320. In the depictedembodiment, the daylighting device 300 includes an insulation structure,or layer, 306 disposed adjacent to, or within, the tube 320. Theinsulation structure 306 can be configured to reduce a rate of thermalenergy transfer between the interior of the daylighting device 300 andthe room 307. For example, the insulation structure 306 can be disposedadjacent to a diffuser 340, such as between the diffuser 340 and theinterior of the tube 320. The insulation structure 306 can be disposedat any other suitable position, such as near the top of the tube 320,near the level of a ceiling, or near the level of the collector 310. Insome embodiments, the insulation structure 306 can be positioned at thesame level as an insulation layer found in the building, and can bepositioned to provide a substantially contiguous layer of insulationtogether with the building insulation layer. The daylighting device 300can also include insulation structures disposed in various positions orlocations. The position(s) of the insulation structure(s) 306 can beselected to produce any desired thermal energy transfer characteristics.

In the embodiment depicted in FIG. 3, the diffuser 340 is disposedadjacent to, and in a substantially parallel alignment with, a surface370 of the roof structure 302. As shown, the tube 320 may extend fromthe light collector 310 and through at least a portion of the roofstructure 302, without extending substantially into the interior roomspace 307. In certain embodiments, the daylighting device 300 caninclude a light collector configured to provide light to the interiorroom 307 without the use of a tube 320. For example, the light collector310 may extend through the roof structure 302, and connect directly withthe diffuser 340.

FIG. 4 shows a cutaway view of an example of a daylighting device 400installed in a building 405. The daylighting device 400 includes a lightcollector 410 mounted on a roof 402 of the building 405 that allowsnatural light to enter a tube 420. In certain building applications,such as high-bay building applications, light provided by a daylightingsystem can be at least partially blocked or undesirably redirected byone or more obstructions disposed in the vicinity of the system's lowerperimeter, or along the path of light between the system and a desiredarea of illumination. The daylighting device 400 can be configured toextend below one or more possible obstructions, or low enough to reducethe effects of one or more obstructions on lighting performance. Incertain embodiments, the effect of obstructions on lighting performanceis reduced by incorporating a daylighting device that maintains asubstantial portion of its transmitted light within a cone half angle ofless than approximately 40-45°. In the depicted embodiment, the tubeextends through the roof 402, and a distance d below a ceiling level409. The ceiling level 409 can be a physical ceiling structure, or mayrepresent a ceiling level in an open-ceiling building configuration. Theceiling level can be, for example, at approximately the same level asone or more I-beam structures, or other building structure. In anembodiment including a physical ceiling structure 409, the daylightingdevice 400 can include an insulation structure disposed adjacent to theceiling level 409.

In certain embodiments, the daylighting device 400 includes a thermalinsulation subsystem, or portion 406, that substantially inhibitsthermal communication between the interior 407 of a structure and theoutside environment. The thermal insulation subsystem can have anysuitable configuration, such as, for example, one of the configurationsdisclosed in U.S. Patent Application Publication No. 2011/0289869,entitled “Thermally Insulating Fenestration Devices and Methods,” theentire contents of which are incorporated by reference and made a partof this specification.

The tubular daylighting device can include a thermal break in anymaterials or components of the daylight device that have high thermalconductivity. For example, a spacer or gap in the sidewall of the tubecan be positioned near a thermal insulating portion and the thermalinsulating portion and thermal break can be configured to form asubstantially continuous layer between the building interior and theexterior environment. In certain embodiments, the insulating portion andthermal break are disposed in the same plane as other buildinginsulation material, such as fiberglass or the like.

FIG. 5 illustrates an embodiment of a daylighting device 500incorporating a collimator 530 at a bottom, or terminal portion of thedaylighting device 500. The bottom portion of the daylighting device 500can include one or more light diffusing or spreading devices 540,thermal insulation devices, or combination of devices referenced herein.Collimator 530 represents an embodiment of the collimator 130 shown inFIG. 1. The collimator 530 serves to generally align rays of lightpropagating through the daylighting device 500 so that light reaches thediffuser 540 at greater angles with respect to the base of the diffuser540 than it would without a collimator. The collimator 530 can be amulti-segment, or multi-stage, collimator. In some embodiments, thecollimator 530 is a single-stage collimator. In certain embodiments,sunlight entering the tube will have a solar altitude (angle from thehorizon) that will remain substantially the same as it reflects down thetube when the tube sides are vertical and parallel. Installation of acollimator, such as a flared out reflective tube, at or near the base ofa tube 520 with the diffuser attached to the base may substantiallyreduce the incident angle of light to the diffuser, which may increasethe diffuser optical efficiency and other system performancecharacteristics.

The daylighting device 500 includes a light collector 510 having aheight h_(c). As used herein, the height h_(c) may refer to the heightof a substantially vertical sidewall portion of the collector 510. Forexample, the substantially vertical sidewall portion may provide avertical daylight-collection surface for daylight incident on certainportions of the collector 510. The light collector 510 can be disposedabout, or adjacent to, the tube 520, which extends through an opening529 in a building. The opening 529 has a width w_(o); the tube 520 has awidth w_(t). The opening of the tube or the opening 529 of the buildingmay provide a target area into which light can be directed by the lightcollector 510 or otherwise received into the daylighting system 500. Incertain embodiments, the height h_(c) of the light collector 510 isgreater than the width w_(o) of the opening 529, and/or width w_(t) ofthe tube/target area. For example, the daylighting installation 500 caninclude, a light collector 510 configured such that the height of thelight collector h_(c) is approximately 1.2 to 2.5 times greater than thewidth w_(t). That is, the height of the light collector h_(c) has anaspect ratio of approximately 1.1-2.1, or 1.2:1 to 2.1:1 with respect tothe width w_(o) of the opening 529. In certain embodiments, the aspectratio is greater than 2.5:1. In certain embodiments, the width we of thetube 520 is approximately 21 inches, and the width w_(o) of the opening529 is greater than, or approximately equal to, the width w_(t) of thetube 520. In certain embodiments, the light collector 510 has a widthw_(c) of approximately 23 inches, a height h_(c) of approximately 36inches, and a collimator 530 terminating in a base having a width ofapproximately 31 inches.

FIG. 6 illustrates an embodiment of the light collector 110 shown inFIG. 1. In certain embodiments, the light collector is configured toturn at least a portion of the light L_(D) striking one of its surfacessuch that the light is directed downwardly toward a horizontal apertureof a tube 620. Various features and characteristics of the lightcollector 610 affect the light turning properties of the collector. Asdisclosed in U.S. Pat. No. 7,546,709, the entire contents of which areincorporated by reference and made a part of this specification, atransparent cover including a smooth outside surface in combination withan internal prismatic element may produce desirable light-turningeffects. In certain embodiments, such a configuration provides a doublerefraction of the sunlight incident on an outside surface of thecollector 610. The collector 610 can be configured to have a continuouscurved shape with respect to one or more dimensions, or may have aseries of curved and/or flat surfaces.

The light collector 610 illustrated in FIG. 6 includes a top surface 612and one or more side surfaces 614. The top surface 612 can besubstantially flat, as shown, or have a slope substantially near zero.Such a configuration may increase an incident angle of light strikingthe top portion 612, which may contribute to higher refraction and/ortransmission values. In certain embodiments, both the top surface 612and one or more side surfaces are associated with light turningcharacteristics. The sidewall portion 614 of the collector 610 maypresent a vertical daylight-collection surface through which daylightmay enter the daylighting device 600. As shown, daylight L_(Ds) mayenter the collector 610 through sidewall 614 at a solar altitude θ₁.Light turning characteristics associated with the sidewall 614 may turnlight L_(Ds) in a direction towards a target area 618, such as anopening in the tube 620, or other building opening. Turning can beachieved through prismatic characteristics of the collector wall orprismatic element or sheet, or other optical element, in associationwith the sidewall 614. In certain embodiments, the resultant solaraltitude θ₂ of L_(Ds) is greater than that of θ₁. In certainembodiments, an aspect ratio between the height of the collector 610 andthe width or diameter of the relevant target area is optimized toimprove performance.

Light turning features of the light collector 610 can include prismaticpatterns formed on a surface of the collector 610. Such a pattern canbe, for example, molded into the inside and/or outside surface of thecollector 610. The pattern can be formed by any suitable method, such asby using a casting, or injection molding technique. In certainembodiments, a prismatic element, or other prismatic structure, isadhered to, connected to, or otherwise associated with the collector610. In certain embodiments, the prisms can be established by horizontalgrooves that are defined by opposed faces that may have a flat or curvedcross-sectional shape. Furthermore, as disclosed further below, groovescan vary in depth and pitch and/or in other respects. Prisms maycircumscribe the entire circumference of the collector 610, and can besubstantially uniform throughout the height or circumference, orperimeter, of a portion of the collector 610. In certain embodiments,prisms/grooves vary with respect to one or more parameters at differentheights or points along the circumference of the collector 610. Forexample, prisms can include faces of varying angles, shapes, and/orwidths, depending on height and/or position. In certain embodiments,portions of the collector 610 are not associated with prismaticstructure.

The top portion 612 of the collector 610 can be associated with lightturning characteristics. For example, as shown, light L_(DT) enteringthe collector 610 through top portion 612 can be turned in a directiontowards the tube opening 618, or opening in a building, such that aresulting solar altitude of the light L_(DT) has a solar altitude of θ₃.In certain embodiments including optical turning elements associatedwith both stet top portion 612 and stet sidewall portion 614, 03 isgreater than θ₂. That is, light L_(DT) striking the top portion 612 canbe turned to a greater degree that light L_(DS) striking the sideportion 614. In certain embodiments, the top portion 612 does notinclude prismatic structure or light-turning characteristics. Forexample, the top portion can include a clear acrylic surface that issubstantially optically transparent. In certain embodiments, the topportion is at least partially optically opaque, or reflective. Suchqualities can be desirable in order to reduce the amount of lighttransferred through the collector 610 into the tube 620 at variouspoints during the day, such as during the middle of the day whensunlight levels are relatively intense.

The tube 620 can be a separate component of the daylighting device 600than the light collector 610. For example, the tube can be an internallyreflective channel of rigid construction, such as having a constructionof aluminum and/or other material that is disposed adjacent to, orconnected to, the light collector 610. In certain embodiments, the tube620 and the collector 610 are integrated such that the two componentssubstantially combined into a single structure.

FIG. 7 illustrates an embodiment of a daylighting system 700 including alight collector with a dome-shaped top portion 712. The dome-shaped topportion 712 may present a surface that is angled (θ) at various pointswith respect to a horizontal plane. Such an angle θ may affect therefractive characteristics of the top portion 712, and may vary alongthe surface of the top portion 712.

The top portion 712 can include any suitable shape. For example, FIG. 8illustrates an embodiment of a daylighting system 800 with a top portion812 having a triangular cross-section. The cross-section of FIG. 8 may,for example, correspond to a light collector having a top portion 812that is conical or pyramidal in shape. The shape, and/or size of thelight collector 810 and/or top portion 812 may depend on various systemconsiderations, such as ease of manufacturing/installation, refractivecharacteristics, aesthetics, and or other considerations. Any suitableshape or size of the top portion (e.g., 712, 812) can be used indaylighting devices constructed or configured according to one or moreembodiments disclosed herein.

Though generally illustrated herein as having a cylindrical, oroval-shaped cross-section in certain embodiments, a light collector inaccordance with the present disclosure may have any suitablecross-sectional shape. Furthermore, the cross-sectional shape of a lightcollector may vary at different points along a vertical axis of thelight collector. FIGS. 9A-9F illustrate embodiments of light collectorshaving various cross-sectional shapes. The various shapes shown in FIGS.9A-9F include square or rectangular 910A, hexagonal 910B, elliptical oroval-shaped 910C, triangular 910D, octagonal 910E, and pentagonal 910Flight collectors. However, the embodiments depicted are provided asexamples only, and a light collector for use in a daylighting system asdescribed herein can be any suitable or feasible shape and/or size.Variously shaped light collectors can be configured to correspond to ashape of a building opening through which a daylighting device transmitslight.

FIG. 10 shows a cross-sectional view of a light collector 1010 includingboth a side portion 1014, and a top portion 1012. The collector 1010 caninclude a transparent acrylic material, or other material that is atleast partially transparent. In certain embodiments, the collector 1010can be manufactured at least partially of transparent acrylic having athickness of approximately 100-125 mm. In certain embodiments, aprismatic element is disposed within or without the side portion 1014,which may provide double refraction of light. For example, asillustrated in FIG. 10, the prismatic element 1015 a can include prismsfacing outward to provide a first refraction of light and a planarsurface of the sheet providing a second refraction. In certainembodiments, this prismatic pattern is molded into a thin polymer sheetthat can be placed inside a protective transparent collector structure.The top portion 1012 can include a variable prism dome. Alternatively,or in addition to, the incorporation of the prismatic element 1015, oneor more walls or surfaces of the collector 1010 can include prismaticfeatures formed therein. While such formed prismatic features can beused, in certain embodiments, a prismatic element may provide desirablelight turning characteristics relatively more efficiently, with respectto cost, ease of manufacture, and/or other considerations.

In certain embodiments, the side portion 1014 is cylindrically shaped,providing a 360-degree sunlight capture zone. The effective lightcapture area of the side portion 1014 can be an area of a cylinder indirect exposure to rays of sunlight, as well as a portion of the topcover 1012 that is directly exposed to the sunlight. In certainembodiments, in the presence of unobstructed, substantially collimatedlight, the effective capture area of the side portion 1014 can beapproximately 90 degrees of the 360 degree circumference of the sideportion 1014, or approximately 25% of the total surface area of the sideportion 1014.

In certain embodiments, the prismatic element 1015 a, with eitheroutwardly-facing or inwardly-facing prisms, extends along the inside ofat least a portion 1017 of the side portion 1014 of the collector 1010.In certain embodiments, sunlight may refract down into the tube if thesunlight is within approximately +/−45 degrees incident angle to thesurface of the side portion 1014 of the collector. The side portion 1014can be hollow, and may extend from the top portion 1012 down,terminating in an open lower end 1018, through which light can pass.

In certain embodiments, the light collector 1012 can be configured suchthat optical elements associated with the side portion 1014 capturesunlight having elevations ranging from 20°-40°, while optical elementsassociated with the top portion 1012 capture incident light at solarelevations greater than approximately 45°. By capturing sunlightincident at a wide range of solar altitudes, the optical elements of thelight collector 1012 can substantially enhance the light collectionperformance of the daylighting device 1000 over a wide range oflatitudes and seasons. As shown in FIG. 10, the light collector 1010 caninclude one or more prismatic elements 1015 a, which extend across atleast a segment 1017 of a perimeter of the side portion 1014. Theprismatic element 1015 a can be a single unitary member, or can includemultiple distinct segments. In certain embodiments that include aprismatic element 1015 a, the prismatic element 1015 a can span theentire side portion 114 of the light collector 1010. Alternatively, asshown in FIG. 10, the prismatic element 1015 a can span a segment 1017of the perimeter of the side portion 1014, but not span a remainingperimeter segment that is contiguous to the spanned segment 1017.

In certain embodiments, a prismatic element 1015 a can include prismsconfigured to refract light. Prisms can include prism grooves on anouter surface of the prismatic element, and can be linear when the sheetis in a flat configuration and, thus, form circles when the sheet 1015 ais formed into a cylindrical configuration. The outer surface of theprismatic element can be positioned against, or proximate to, an innersurface of the side portion of the collector. The prism grooves can beoutwardly facing, as shown in FIG. 10, or otherwise configured. Incertain embodiments, similar prisms are present in both the top portionand the side portion, both serving to increase light throughput. Thevarious prism elements included in the light collector 1010 can havedifferent prism angles, depending on what portion of the collector 1010they are associated with. In certain embodiments, the prism elements inthe light collector 1010 have uniform prism angles throughout thecollector 1010. In certain embodiments, prisms within a single region ofthe collector 1010 have varying prism angles. For example, it can bedesirable for adjacent prisms, or adjacent groups of prisms, to includedifferent prism angles in order to mix the light that propagates througha portion of the light collector 1010. For example, if substantiallycollimated light enters a prismatic portion of a light collectingassembly that includes prisms with equal prism angles, light enteringthe tube can be concentrated in certain regions. Such lightconcentration may cause undesirable “hot spots” in the destination area.By varying the prism angles, the effect of such hot spots can bereduced.

The top portion 1012 can be made integrally with the side portion 1014and may extend from an open base 1018 to a closed top portion 1012,forming a continuous wall. Alternatively, the top portion 1012 can be anat least partially separate physical component from the side portion1014. In the depicted embodiment, the top portion 1012 is substantiallyflat, and can be associated with one or more optical components, such asa prismatic element 1015 b. However, as discussed above, the top portion1012, or any other portion of the light collector 1010, can be shaped inany suitable manner.

In certain embodiments, the top portion 1012 is at least partiallyconstructed of transparent acrylic. The top portion 1012 can be formedwith prismatic elements, which can be prism lines that are etched in,molded in, or otherwise integrated with or attached to the top portion1012. In certain embodiments, the prism elements increase lightthroughput by capturing light originating outside the collector 110 andturning it downward through the open base portion 1018, and into a tubeassembly. Prismatic elements associated with the top portion 1012 maydiffer from those associated with the side portion 1014. For example,the prismatic element 1015 b can include prismatic grooves havingopposing faces that lie at angles of approximately 45° and 18°,respectively, with respect to a vertical plane. Prisms including facesthat lie at other angles are also contemplated with respect toembodiments of top, side, and/or other portions of light collectingassemblies disclosed herein.

FIG. 11 provides a cross-sectional view of a portion of the prismaticelement 1015 a shown in FIG. 10. The portion of the prismatic element1015 a shown in FIG. 11 includes a plurality of prisms 1156. Thestructure shown in FIG. 11 includes an outer transparent side portion1114 of the light-collecting assembly 1010 of FIG. 10. The prisms 1156can be positioned along the interior surface of the side portion 1114,and may face the direction of sunlight L_(S) penetrating the sideportion 1114. In certain embodiments, prisms 1156 are inwardly facing,with back surface 1149 of the prisms facing the side portion 1114. Incertain embodiments, prismatic element 1115 contains prisms on more thanone of its sides. The prisms can be configured to turn at least aportion of sunlight that strikes the cylinder portion of the lightcollecting assembly downward towards a horizontal aperture of a tube.

In certain embodiments, prisms 1156 include two faces 1146, 1148. In theembodiment of FIG. 11, face 1148 has a prism angle γ₁ with respect tohorizontal, while face 1146 has a prism angle γ₂ below horizontal. Theprism angles γ₁ and γ₂ can be equal, or may vary, depending on theconfiguration of the prismatic element 1115. Furthermore, adjacentprisms 1156, or groups of prisms, may have varying prism angles. Suchvarying prism angles may promote mixing of light propagating through alight collector. In certain embodiments the prismatic element 1115includes prisms having uniform prism angles. In certain embodiments, theprism angles γ₁ and γ₂ have angles of approximately 70° and 30°,respectively.

With further reference to FIG. 10, prism angles associated with the topportion 1012 and the side portion 1014 can be selected to provide anangle of refraction that increases the range of solar altitudes at whichradiation that can be captured and turned towards the daylightingaperture 1018 at the base of the light collector 1010. In certainembodiments, the light collector 1010 and prismatic element are made ofthe same material or materials, or materials having substantiallysimilar indexes of refraction. In some embodiments, the prismaticelement(s) can include a material or materials with higher index ofrefraction than a sidewall of the light collector.

The top portion 1012 can be configured to reduce the effective capturearea of the light collector 1010 at solar altitudes higher than acertain value to prevent over illumination and/or heating during middayhours (such as, for example, between 10 am and 3 pm, between 11 am and 2pm, or during a time when the solar altitude is greater than or equal toabout 30 degrees). In certain embodiments, at least a portion of the topportion 1012 can be configured to reflect some or all of the lightstriking such portion at solar altitudes above a certain angle. Forexample, at least some of the top portion 1012 can be configured toreflect at least a portion of overhead sunlight in order to reduce lightand/or heat during midday hours. Embodiments of the light collector 1010with a prismatic element 1015 b positioned to receive daylighttransmitted through the top portion 1012 can be beneficial in sunny andhigh solar altitude conditions. A prismatic element 1015 b in the topportion 1012 can direct a substantial portion, most, or substantiallyall daylight incident on the top portion 1012 towards a reflector, suchas, for example, the reflector 1980 shown in FIG. 19. The reflector canbe configured to reject wavelengths of daylight that transmit thermalenergy but provide little or no visible illumination.

In certain embodiments, the top portion 1012 of the light collector 1010can be constructed at least partially from clear acrylic, transparentplastic, another suitable material, or a combination of materials.Embodiments of the light collector 1010 with a clear top portion can bebeneficial in diffuse daylight conditions due to relatively hightransmission of overhead sunlight.

The walls of the side portion 1014 can be substantially vertical, or mayhave any desirable inward or outward slope. In certain embodiments, thewalls of side portion 1014 are sloped to allow for nesting of multiplesuch components to allow for tighter packaging.

In certain embodiments, the side portion 1014 provides a substantiallyvertical daylight-collection surface for sunlight collection, which mayprovide higher aspect ratios for light collection. Prismatic elementscan be integrated with at least a portion of the wall of the sideportion 1014. In alternative to, or in addition to, prisms integrated inthe side portion 1014, the above-described prismatic element can be usedto refract light downward. The planar back side 1149 of the prismaticelement 1115, shown in FIG. 11, may provide good downward refraction dueto a high to low index of refraction interface. Certain light collectorembodiments include a plastic polymer with an index of refraction in therange of approximately 1.49-1.65.

FIG. 12 shows a cross-sectional view of a light collector 1210 includinga side portion that includes a plurality of vertically arranged opticalzones, or segments 1214 a, 1214 b, and 1214 c. In certain embodiments,various segments are associated with prismatic elements having differentprism angles or characteristics. For example, a top segment, such assegment 1214 a, can be associated with light turning structure 1213 aconfigured to turn light at a relatively high angle towards the base1218 of the light collector 1210. This can be desirable in order toincrease the percentage of light L₁ entering the top segment 1214 a thatis directed through the base 1218 of the light collector 1210 and into atube 1220. As light entering the top segment 1214 a has a relativelyfarther distance to travel in order to reach the base 1218, it can benecessary or desirable to turn such light to a relatively high angle.Relative to the prismatic structure 1215 a, the prismatic structure 1215b that is associated with the second segment 1214 b can includeprismatic angles that turn light L₂ to a lesser degree than L₁ isturned. This can be desirable due to the prismatic structure 1215 bbeing disposed generally closer to the base 1218. Therefore, it may notbe necessary to turn light L₂ as much to facilitate the propagation oflight entering the light collector 1210 through the second segment 1214b to a desirable degree.

The light collector can include one or more portions or segments, suchas segment 1214 c, that are not associated with prismatic structures.For example, a segment, such as segment 1214 c, disposed relatively nearto the base 1218 may require relatively less turning of light, or noturning of light to achieve desirable levels of light collection.Therefore, as shown, light L3 entering the bottom segment 1214 c mayenter the tube 1220 substantially without being refracted toward thetube by the light collector 1210.

Although the light collector illustrates three segments, a lightcollector in accordance with certain embodiments disclosed herein maycontain any number of segments or regions. Furthermore, differentsegments can be associated with optical elements having varyingcharacteristics, or can be uniform through one or more segments.

As shown in FIG. 12, the width w_(c) of the collector base 1218 can begreater than the width w_(d) of the tube 1220 at a horizontal aperture.For example, the diameter of the collector base 1218 may range from 100%to 150% or more of the width of the tube 1220.

In certain embodiments, a flat or curved reflective panel is associatedwith a light collector that reflects at least a portion of sunlight thatwould otherwise exit the light collector through a portion generallyopposite to a region of the light collector through which daylight isreceived. FIG. 14A provides a perspective view of an embodiment of alight reflector 1480 for disposing within, adjacent to, or inintegration with, a light collecting assembly. The reflector can be madeof material having high luminous reflectance. For example, the luminousreflectance of the reflector 1480 can be greater than or equal to about0.9, greater than or equal to about 0.95, greater than or equal to about0.98, or greater than or equal to about 0.99, when measured with respectto CIE Illuminant D₆₅. The reflector 1480 can be curved, as shown, orcan be any shape configurable to reflect light propagating within ornear a light collecting assembly.

As is shown in FIG. 14B, which provides a top view of the reflector 1480of FIG. 14A, the reflector 1480 can be semi-circular in shape, such thatit can be nested within a cylindrically-shaped light collector. Thereflector 1480 may conform to the shape of a back portion of a lightcollecting assembly, and can be disposed behind a refractive lens,thereby increasing the effecting light capture area of the lightcollector. The reflector 1480 may provide increased transmission ofcaptured sunlight into an optical guide tube.

The use of a curved reflector 1280 may allow for sunlight capture from agreater range of circumferential angles about the light collector 1220.This increase in angular reflection of sunlight may provide a number ofbenefits, such as increased light mixing. For example, in embodiments inwhich sunlight enter a tube opening from a wide range of circumferentialangles, the distribution of light exiting the tube can be more uniformand may reduce the presence of hot spots on a diffuser at the base ofthe tube. Such light mixing can prevent collimated light from reachingthe diffuser prisms in such a way as to cause rainbows to appear in thebuilding interior.

With respect to certain embodiments in which light is directed into acentral feeder tube, and dispersed into multiple branch tubes, lightmixing can be important in promoting the dispersion of sunlight into thevarious branch tubes. In certain embodiments, branch tubes each receiveapproximately equal amounts of light from the central feeder tube.

The collection and redirection of sunlight using a light reflector, suchas the curved reflector 1480, may substantially increase the performanceof a conventional tubular daylighting device. A number of parameters maycontribute to increased performance of certain embodiments ofsunlight-collection systems. For example, the sunlight collection areaof a light collector may affect the performance of such a system. Incertain embodiments, the height and width of the collector in relationto the diameter of a tube opening into which light is directed can bedetermined by the refractive turning power of optical elements (e.g.,integrated prisms, prismatic element or lens film, etc.) within, orassociated with, the light collector. This aspect ratio of cylinderheight to tube opening width, or diameter, may depend on the solaraltitude range that is desired to capture and refract into the tube.This range can be from approximately 20 to 70 degrees for most locationsin the United States. For example, using lower-end solar altitude ofapproximately 20 degrees as the design point for refracting light intothe tube from the optical elements associated with a light collectorhaving vertical side walls, the cylinder height can be designed to anapproximate range of 1.2 to 2.5 times the tube diameter. These valuesmay vary based on material index of refraction and prism angles, amongother things. As an example, a system can include a collector height ofapproximately 35-45 inches and a tube diameter of approximately 20-25inches. The diameter of the collector can be approximately equal to thediameter of the tube opening, or can be larger or smaller than thediameter of the tube. The actual effective front light-capture area ofthe cylinder is associated with the direct non-reflected sun, which, incertain embodiments, can be limited to an exposure angle ofapproximately 90 degrees due to the off axis curvature limitation of theoptics in the collector prisms.

FIG. 14C provides a cross-sectional view of the vertically-orientedplanar reflector 1480. As is shown in the figure, the angle θ₁ of directlight L_(D) with respect to a horizontal plane is generally equal to theangle θ₂ of reflected light L_(R). In certain embodiments, it can bedesirable for the reflector surface to be tilted with respect to avertical axis to increase the reflected angle θ₂ with respect tohorizontal. Furthermore, in certain embodiments, the reflector 1480 isassociated with one or more prismatic surfaces that further increase theangle of reflected light. Such prisms may vary over different portionsof the reflector in order to increase the amount of light received intoa tube opening.

FIG. 15 illustrates a perspective view of an embodiment of daylightingdevice 1500 including a light collector 1510 incorporating a reflector1580. The daylighting device 1500 includes a light-reflecting tube 1520disposed adjacent to the light collector 1510. As shown, daylight L_(S)enters the light collector 1510 through a side portion 1514. The lightL_(S) is refracted by one or more optical elements associated with theside portion 1514 and turned towards an opening in the tube 1520. Incertain embodiments, the side portion 1514 is not associated with lightturning characteristics, and light L_(S) entering the light collector1510 propagates within the light collector at an angle substantiallyequal to the angle of the light L_(S) prior to entering the lightcollector 1510. The presence of the reflector 1580 may increase theeffective area of collection of one or more refractive lenses associatedwith the light collector and configured to turn light towards the tube1520.

The reflector 1580 is disposed along an inside or outside surface of thelight collector 1510, such as along a surface that is positionedsubstantially opposite to a direction at which light L_(S) may enter thelight collector 1510 at one or more points during the day. For example,the reflector 1580 may generally face in a southern direction in anembodiment located at a point in the northern hemisphere. As shown,daylight L_(S) may enter the light collector 1510 and strike a point onthe reflector 1580. The reflector may reflect at least a portion of thedaylight in the visible spectrum towards the tube opening 1528. If notfor the reflector, a substantial portions of the light L_(R) may insteadpropagate out of the tube or be absorbed by materials associated withthe light collector 1510. Therefore, inclusion of a reflector 1580 in adaylighting system 1500 may increase the amount of light transmittedthrough the light collector 1510 into the tube 1520.

FIG. 16 illustrates a perspective view of an embodiment of daylightingsystem 1600 including a light collector 1610 incorporating a reflector1680. The reflector 1680 can include characteristics allowing forpass-through transmission of certain amounts of light of certainwavelengths. For example, in certain embodiments, the reflector 1680 isat least partially transparent with respect to light in the infraredspectrum. Sunlight includes infrared light and visible light. Ingeneral, infrared light transfers thermal energy but provides little orno advantage when the goal is illumination. A daylighting device thatdirects infrared light into a building can substantially increasetemperatures within the building without providing any measurableillumination benefit. In some embodiments, a light collector includes areflector that allows at least a portion of infrared light that isincident on its surface to pass through the reflector and out of thelight collector 1610, rather than reflecting such light in the directionof the tube 1620. In certain embodiments, a light collector 1610 isconfigured to capture and remove at least a portion of infrared lightincident on the collector and/or other spectral wavelengths that do notcontribute to visible illumination. In such embodiments, the lightcollector 1610 can simultaneously turn a substantial portion of visiblelight, such as, for example, greater than or equal to 95%, greater thanor equal to 98%, or greater than or equal to 99% of visible light,towards a daylighting aperture formed in the base of the collector 1610.

The dashed line in FIG. 16 shows a possible path of sunlight that iscaptured by the light collector 1610. When incident on an outsidesurface of the collector 1610, the sunlight includes visible andinfrared light. At least a portion of the light incident on the surfaceof the at least partially transparent light collector 1610 passes intothe interior of the light collector 1610. The light propagates withinthe light collector 1610 until it strikes a reflector 1680 positioned toreceive at least a portion of the light entering the light collector1610. In certain embodiments, the reflector 1680 is disposed along aninner or outer surface of a substantially vertical sidewall the lightcollector 1610. In some embodiments, the light transmits through asecond transparent sidewall of the light collector before propagating toa surface of the reflector 1680. The reflector 1680 is configured toturn at least a portion of the light in a direction generally towards anopening of a tube 1620 positioned to receive light that exits thedaylight collector 1610 through a daylighting aperture in the base ofthe collector. In some embodiments, the reflector 1680 is at leastpartially transparent to infrared light L_(IR). In such embodiments, aportion of the infrared light L_(IR) transmits through the reflector1680 and exits the light collector 1610, propagating away from theopening of the tube 1620.

In certain embodiments, the reflector 1680 is configured to transmitwavelengths other than infrared. For example, the reflector 1680 canpartially reflect and partially transmit visible light. As anotherexample, the reflector 1680 can reflect most or substantially allvisible light while transmitting and/or absorbing at least a portion ofultraviolet light.

FIG. 17A illustrates an embodiment of a light collector 1710 having atransparent assembly and a reflective assembly. The light collector 1710includes a transparent assembly 1711 that is at least partiallytransparent to daylight incident on its surface. For example, thetransparent assembly 1711 can include a sheet of substantially clearacrylic in a semi-circular, curved, planar, and/or segmentedconfiguration. The reflective assembly 1780 can include material forreflecting at least a portion of light incident on one or more of itssurfaces. For example, the reflective assembly 1780 can be asemi-circular, curved, planar, and/or segmented reflector. In certainembodiments, the reflective assembly 1780 includes aluminum, reflectivefilm, a metallic reflector, other reflective materials, other opticalelements, or a combination of optical elements.

The transparent portion 1711 and the reflector assembly 1780 can beconnected at a seam 1730 to form a combined structure, such as anenclosed cylinder or other shape. The structures can be combined in anysuitable manner. For example, the structures can be adhered togetherthrough the use of an adhesive substance, or by welding or othertechnique. In certain embodiments, the structures 1711, 1780 areconnected using one or more physical connection structures, such asclips, slots, staples, and the like. For example, as shown in FIG. 17B,which provides a top view of a portion of the light collector 1710, oneor more end portions of the respective structures can includemale/female slot connecting members for connecting two or morestructures. Such a configuration may allow for connection of structureswithout the need of additional separate connecting devices or materials.

FIG. 18 illustrates an embodiment of a light collector 1810 having atransparent portion and a reflector assembly. Depending on materialcharacteristics of the reflector assembly 1880, portions of thereflector assembly, or any other component of the light collector 1810,may absorb thermal energy from light (e.g., infrared light) coming incontact therewith. For example, in certain embodiments, the reflectorassembly can include aluminum. Heat absorbed by such a structure maycontribute to undesirable heating within a light collector, daylightingsystem and/or interior of a building.

In certain embodiments, an outside surface 1881 of at least a portion ofthe light collector 1810 is coated or covered with a layer of materialhaving a relatively high thermal emissivity factor, serving to aid inthe transfer of thermal energy away from the light collector 1810. Theemissivity factor is related to the ratio of absorbed thermal energy toreflected and/or transmitted thermal energy. In certain embodiments, theoutside surface 1881 is in thermal communication with a material havingan emissivity factor of greater than about 0.9. Furthermore,high-emissivity material(s) used in connection with a light collectorsuch as that depicted in FIG. 18 may have varying emissivitycharacteristics for different wavelengths of light. For example, amaterial can be configured to transmit a relatively high percentage ofenergy in the infrared spectrum. Material in thermal communication withouter surface 1881 can be in the form of paint or other coating, or canbe a sheet or film disposed in the surface 1881. Other components of thedaylighting system, such as a daylight-reflective tube, can be coated orlined with high-emissivity materials in order to draw heat away from theinterior of the daylighting system, thereby reducing unwanted heating.Examples of types of high-emissivity materials that can be used inconnection with a daylighting apparatus include various types of glass(e.g., frosted glass), plastic, sheet metal, paint, powders (e.g.,graphite powder), lacquer, or tape (e.g., electrical tape) havinghigh-emissivity characteristics, and can be black or white in color.High-emissivity material can be used in connection with variousembodiments of light collecting assemblies as disclosed herein,including light collectors of having any suitable shape or including anysuitable material or combination of materials.

FIG. 19 illustrates an embodiment of a light collector 1910 in adaylighting system 1900. The light collector includes threevertically-arranged optical zones, or segments 1914 a, 1914 b and 1914c. The segments 1914 a, 1914 b and 1914 c can be of uniform height, orthe heights of different segments may vary. In certain embodiments, eachsegment is approximately 10-15 inches tall. For example, the segments1914 a, 1914 b and 1914 c can be approximately 12 inches in height. Incertain embodiments, a bottom segment, such as segment 1914 c, has agreater height than other segments to accommodate attachment of thelight collector 1910 to a flashing. For example, the bottom segment 1914c may have a height of about 14 inches. Furthermore, the light collectorcan include a lip, or fringe f that extends beyond the opening of thetube 1920.

Although three segments are shown, a light collector can include anysuitable number of segments or portions. In certain embodiments,different segments can be associated with different optical refraction,transmission and/or reflection characteristics. For example, in someembodiments, at least a portion of the top segment 1914 a is associatedwith a prismatic element 1915 a, or other optical element or elements.As shown in FIG. 19, the prismatic element 1915 a may extend around morethan half the circumference of a generally cylindrically-shaped lightcollector 1900. In certain embodiments, the prismatic element 1915 aextends around approximately 270° of the cylindrically shaped collector1910, and may generally face a direction from which daylight enters thecollector 1910, as shown. Providing prismatic element that extendsbeyond 180° of the perimeter of the light collector may allow forcapture of a wider spectrum of light. In certain embodiments, theprismatic element 1915 a circumscribes the entire perimeter of the lightcollector 1910, at least with respect to the top segment 1914 a.

In the depicted embodiment, the middle segment 1914 b is also associatedwith light turning structure 1915 b, such as prismatic element. Aprismatic element 1915 b can extend along approximately 50%, or 180°, ofthe perimeter of the light collector 1910, as shown, and can generallyface a direction from which daylight enters the collector 1910. Theprismatic elements 1915 a and 1915 b can be a unitary structure, or canbe separate sheets or films. The prismatic elements 1915 a and 1915 bcan include prisms having similar or different light-turningcharacteristics. In certain embodiments, one prismatic element 1915 a isconfigured to turn daylight to a greater degree than another prismaticelement 1915 b.

Collector segment 1914 c can be associated with light-turning prismaticstructure, or may not, depending on collector 1910 characteristics. Forexample, as shown, the segment 1914 c may allow for daylight to passinto the collector 1910 without substantially altering an angle of thedaylight with respect to a horizontal plane. Therefore, the segment 1915c may present a substantially clear acrylic material without additionaloptical elements to daylight entering therein.

In addition to, or in place of, a light turning structure 1915 a, 1915b, one or more portions or segments of the light collector 1910 can beassociated with a reflector assembly 1980. In the embodiment shown inFIG. 19, a reflector 1980 is disposed in proximity to an inside surfaceof the sidewall of the light collector 1910 along portions of lightcollector segments 1914 b and 1914 c. It can be desirable to include oneor more reflectors in at least a lower portion of the light collector1910 because light striking a reflector in a lower portion of the lightcollector 1910 can be more likely to reflect into the tube 1920 ratherthan exiting out the front side of the collector. For example, in anembodiment including a reflector in the top segment 1914 a, lightstriking the reflector at a point in segment 1914 a may have a furtherdistance to travel in order to reach the tube 1920. Therefore, the angleof trajectory may carry the light out of the collector before it reachesthe tube 1920. In certain embodiments, the top segment 1914 a of thecollector 1920 is not associated with the reflector assembly 1980. Insome embodiments, a light collector 1910 having a reflector 1980 canhave a height that is greater than or equal to about twice the height ofa light collector that does not have a reflector. In some embodiments, alight collector 1910 having a reflector 1980 limits the collection oflight at sun azimuthal angles greater than 60 to 90 degrees when thereflector 1980 is facing south.

Reflective characteristics of the reflector 1980 may vary in differentportions or segments of the reflector. Furthermore, while FIG. 19 showsthe reflector as a singular piece, the reflector can include distinctpieces or structures. The reflector 1980, or portions of the thereof mayspan any suitable portion of the circumference, or perimeter, of thelight collector 1910. In certain embodiments, the reflector 1980 spansapproximately 180° of the light collector's perimeter, as shown. Thereflector can be positioned generally at a back portion of the lightcollector with respect to a direction from which daylight enters thelight collector 1910. In certain embodiments, and under certain daylightconditions, the light collector 1910 and reflector 1980 can beconfigured such that approximately 85% or more of the light entering thecollector will be directed to the reflector 1980, and can allow for theremoval of infrared light from daylight before the daylight enters thetube 1920.

The reflector 1980 can be constructed from a material system that hashigh luminous reflectance and high transmittance of infrared light. Thefinish of the reflector 1980 can be specular or have any desired levelof specularity. Wavelength-selective light reflectance can be achievedusing any suitable materials. Examples of wavelength-selective materialsystems include dielectric coatings and/or multi-layer films that usesmall differences in refractive index between many layers of the film toachieve desired optical properties. Multi-layer films can includecoextruded stacks of two or more polymers having different refractiveindices. FIG. 13 shows the reflectivity profile of a multi-layer film,3M Daylighting Film DF2000MA, which is available from the 3M Company ofMaplewood, Minn., USA. This polymeric film is an example of amulti-layer film that can be part of the material system of thereflector 1980 or as the reflector 1980. The reflectivity profile of aenhanced silver coating is also shown. The multi layer film providesvery high reflectivity in the visible region, having a luminousreflectance greater than 99% when measured with respect to CIEIlluminant D₆₅. The film has substantially lower reflectivity ofinfrared light; the reflectivity of infrared light is less than or equalto about 20%. The reflectivity of ultraviolet light is alsosubstantially lower than the reflectivity of visible light. Incomparison, the enhanced silver coating has lower luminous reflectanceand infrared light reflectivity greater than 90%.

After infrared light is transmitted through a wavelength-selectivereflector 1980, the infrared light can transmit through an infraredtransmissive material, such as, for example, acrylic or PET. In someembodiments, the sidewall of the collector 1910 is made from an infraredtransmissive material. In some embodiments, the infrared light isabsorbed after transmitting through a wavelength-selective reflector1980. In such embodiments, the infrared light can be absorbed by aninfrared absorbing paint or adhesive positioned to receive the infraredlight after it transmits through the reflector 1980. In someembodiments, the infrared paint or adhesive is adhered to a metalsubstrate. The metal substrate can form a portion of the sidewall of thecollector that is not transparent (e.g., a portion of the sidewallconfigured to face away from direct sunlight). The metal substrate canbe heated by the paint or adhesive when it absorbs infrared light, andthe infrared light can then be reemitted in a direction generally awayfrom the daylighting aperture 1918 and the tube 1920.

In some embodiments, an exterior surface of the portion of the sidewallof the collector 1910 that absorbs infrared light has high emissivity.High emissivity can be obtained by applying a high emissivity material,such as paint, to the surface, or by performing another type of surfacetreatment, such as anodization. At least some anodized metals exhibithigh emissivity, and such metals can form at least a portion of theexterior surface of the light collector 1910. A high emissivity surfacecan also be provided on the outside surface of the tube 1920, which canpermit the tube 1920 to readily reemit infrared radiation absorbed bythe tube 1920 out of the daylighting device 1900.

In certain embodiments, the daylighting device 1900 is configured toreject heat during summer months, when the solar altitude is higher, andto direct heat into the building being illuminated by the daylightingdevice during winter months, when the solar altitude is lower.

A daylighting device incorporating a light collector in accordance withthe embodiments described above can be configured to maintain anillumination level within a range of about +/−20% of a given valuethroughout a period of interest, such as the hours from around 9:00 amto 3:00 pm. Furthermore, such a device may provide around 20,000 lumensof light, or more, at a given time, depending on, among other things,external daylight conditions.

Table A lists potential illumination performance values of two daylightcollectors in accordance with one or more embodiments disclosed herein.The performance can be measured by total daylight transmission (inlumens) through the daylighting device into an interior space of abuilding or structure. In some embodiments, the illumination performanceof a daylight collector can be determined by measuring the luminous fluxof daylight through the daylighting aperture of a daylight collector.Table A provides potential results with respect to a range of daylightconditions/solar altitudes. In some embodiments, a daylighting collectoris configured to direct greater than or equal to about 30,000 lumensand/or greater than or equal to about 40,000 lumens of daylight into adaylighting aperture when the daylighting collector is exposed tosunlight at a solar altitude of 40°.

TABLE A Light Transmitted - Light Transmitted - 23″ cylinder 27″cylinder Solar altitude with 45°/10° with 45°/10° (degrees fromprismatic element at prismatic element at horizontal) top (lumens) top(lumens) 20 18,284 24,900 30 27,799 36,857 40 30,318 40,730 50 28,57538,219 60 24,523 33,928 70 23,155 32,558 80 10,394 16,494

FIG. 20 illustrates an embodiment of a light collector 2010. The figureshows two vertically-arranged zones, or segments, ‘A’ and ‘B.’ Thesegments A and B can be of uniform height, or the heights of differentsegments may vary. In certain embodiments, the segment A represents aportion of a vertical side portion of the light collector 2010 that isassociated with prismatic structure 2015 a, at least over some portionof the circumference or perimeter of the side portion. Furthermore, thesegment B may represent a portion of the vertical side portion of thelight collector 2010 that is not associated with prismatic structure.The light collector 2010 can include a back half-cylinder portion, whichcan include reflective properties. For example, at least a portion ofthe back portion 2080 can include or be associated with aluminum, orother reflective material. In certain embodiments, the vertical walls ofthe light collector 2010 can be configured to capture daylight having asolar altitude of approximately 20°-50°.

The light collector 2010 can include a substantially clear dome-shapedcover portion 2012. The cover portion 2012 can be configured to capturedaylight having a solar altitude of approximately 30°-90°. Thecombination of vertical sidewall and dome-shaped cover portions mayprovide improved performance during both clear and cloudy weatherconditions.

In general, with respect to a light collector embodiments in accordancewith FIG. 20, greater performance a lower solar elevations (e.g.,20°-40°) can be achievable with higher aspect ratios (i.e., height ofvertical cylinder portion C vs. width of tube opening w_(t)). Withrespect to daylight at solar altitudes greater than 40°, the horizontaldaylight-collection surface provided by the cover 2012 may provide themajority of daylight capture. In certain embodiments, an aspect ratio ofapproximately 1.9 will produce approximately 40% or more improvement incaptured light at 20° and/or 30° when compared to an aspect ratio ofapproximately 1.3 or less. However, performance at 40°-90° may remainapproximately steady for both configurations.

Design considerations in manufacturing daylight collectors in accordancewith one or more embodiments disclosed herein may take intoconsideration various cost-related and/or other factors. For example,different materials that can be selected for incorporation in a daylightcollector can be available at different prices. Furthermore, differentmaterials may have different physical properties contributing to theperformance and/or ease of manufacturing of various components of thecollector. Therefore, certain information about the physical dimensionsof a light collector can be useful in making design or other decisions.Table B provides example physical specifications for a number ofpossible embodiments of daylight collectors. The dimensions provided inTable B correspond to the areas and dimensions called out in FIG. 20.Table B provides size and area information that can be helpful inassessing cost/performance issues associated with the respectiveembodiments, as well as other embodiments.

TABLE B Scaled-Up Scaled-Up High Aspect High Aspect Low Aspect LowAspect Collector Type Ratio Ratio Ratio Ratio Cylinder Diameter (W_(c))23″   27.3″ 23″   27.3″ Tube Diameter (W_(t)) 21″   25.3″ 21″   25.3″ A23.6″ 28.2″ 10.4″ 12.5″ B 18.0″ 21.1″ 18.0″ 21.1″ C 41.6″ 49.3″ 28.4″33.6″ Cover (2012) Surface 2.88 ft² 4.09 ft² 2.88 ft²  4.09 ft² AreaFront Prismatic Portion  5.9 ft² 8.40 ft² 2.6 ft²  3.7 ft² (2015a) AreaFront Prismatic Portion 23/6″ × 36.1″ 28.2″ × 42.8″ 10.4″ × 36.1″ 12.5″× 42.8″ (2015a) Size Back Portion (2080) Area 10.4 ft² 14.7 ft² 7.2 ft²10.0 ft² Back Portion (2080) Size 41.6″ × 36.1″ 49.3″ × 42.8″ 28.4″ ×36.1″ 33.6″ × 42.8″

The values provided in Table B are approximations of various possibledaylight collector dimensions, and are not limiting on the scope of thedisclosure in any way. Furthermore, although certain values are providedin the table, the respective collector dimensions need not conform inany way to such values, and can be configured to be any suitabledimensions. As shown in the table, construction of a daylight collectormay demand more than 8 ft² of prismatic material, as well as more than14 ft² of reflective back portion material. Therefore, costs associatedat least with such materials/areas may represent a significant factor indaylight collector design.

In certain embodiments, a light collector in accordance with one or moreembodiments described herein can be configured such that fabricationand/or installation of the collector are simplified. For example, theside portion of a light collector 2014 can be formed from asubstantially flat or curved sheet that can be formed into a cylinder,as shown by the top view of FIG. 21A. Such a configuration, asinstalled, may have a singular vertical seam that can be, for example,secured by an attaching member 2019, or in any other suitable way.

FIG. 21B shows top view of an embodiment of a portion of a lightcollector, wherein the circumference of the light collector is made upof multiple segments 2114 a, 2114 b and 2114 c, that can be attached inany suitable manner, such as by using attaching members 2119 a, 2119 b,and/or 2119 c. With respect to the embodiments depicted in both FIGS.21A and 21, a flat, slightly curved, or otherwise shaped top cover canbe placed on the cylinder top.

FIG. 22 illustrates a packaging configuration for one or more curvedlight collector portions. For example, with respect to the embodimentsof FIGS. 20 and 21, which can include one or more curved panels that canbe formed into a cylinder or other shape, such panels can be disposed ina stacked configuration in a package 2290 for shipping, transporting,storing, or for other purposes. FIG. 23 illustrates a packagingconfiguration in which one or more curved panels 2314 a, 2314 b, 2314 care concentrically arranged in a package 2390. The packages shown canallow space for prismatic and/or reflective components, or any othercomponents, associated with a daylighting device. Such packagingconfigurations may reduce cost and/or effort associated with themanufacture, transportation, and/or installation of one or morecomponents of a daylighting device.

At least some of the embodiments disclosed herein may provide one ormore advantages over existing lighting systems. For example, certainembodiments effectively allow increased daylight capture through the useof a light collector incorporating one or more prismatic elements and/orreflective elements. As another example, some embodiments providetechniques for directing light to a building interior using a lightcollector having a height greater than the width of an opening in thebuilding, or of a base aperture of the collector, through which light istransmitted. The height of the collector may provide an increased targetlight capture area. Certain embodiments may provide additional benefits,including reducing the incident angle at the diffuser of lightpropagating through the daylighting device, which can result in thediffuser operating with higher optical efficiency.

OTHER EMBODIMENTS

The following list has example embodiments that are within the scope ofthis disclosure. The example embodiments that are listed should in noway be interpreted as limiting the scope of the disclosure. Variousfeatures of the example embodiments that are listed can be removed,added, or combined to form additional embodiments, which are part ofthis disclosure:

1. An at least partially transparent light-collecting device configuredto direct daylight through a collector base aperture and into aninterior of a building when the light-collecting device is installed ona roof of the building, the device comprising:

-   -   a top cover portion;    -   a substantially vertical sidewall portion configured to support        the top cover portion above an upper end of the substantially        vertical sidewall portion and to define a collector base        aperture at a lower end of the substantially vertical sidewall        portion, wherein the substantially vertical portion has a height        that extends between the top cover portion and the collector        base aperture, and wherein the substantially vertical portion is        configured to receive a substantial amount of daylight during        midday hours;    -   a prismatic element associated with the substantially vertical        sidewall portion and configured to turn at least a portion of        daylight received by the vertical portion towards the collector        base aperture; and    -   a reflector associated with the substantially vertical portion        configured to reflect the portion of daylight towards the        opening;    -   wherein the light-collecting device is configured to be        positioned over an opening in a roof of a building and is        configured to direct daylight into the opening in the roof when        the light-collecting device is installed as part of a        daylighting device installation.

2. The device of embodiment 1, wherein the height of the verticalportion is greater than the width of the collector base aperture.

3. The device of embodiment 2, wherein an aspect ratio of the height ofthe vertical portion to the width of the collector base aperture isgreater than 1.2 to 1.

4. The device of any of embodiments 1-3, wherein the top cover portionis substantially flat.

5. The device of any of embodiments 1-4, wherein the top cover portioncomprises a dome-shaped surface.

6. The device of any of embodiments 1-5, wherein the top cover portioncomprises a cone-shaped surface.

7. The device of any of embodiments 1-6, wherein the vertical portioncomprises a plurality of vertically-arranged segments, including a topsegment, a middle segment, and a bottom segment.

8. The device of embodiment 7, wherein the top segment is associatedwith first optical elements having first light-turning characteristicsand the middle portion is associated with second optical elements havingsecond light-turning characteristics.

9. The device of any of embodiments 7-8, wherein the bottom segment isnot associated with light-turning optical elements.

10. The device of any of embodiments 7-9, wherein the top, middle, andbottom segments are each approximately 5 to 10 inches in height.

11. The device of any of embodiments 7-10, wherein the top, middle, andbottom segments are each a uniform height.

12. The device of any of embodiments 7-11, wherein the reflector is atleast partially transparent with respect to infrared light.

13. The device of any of embodiments 7-12, wherein the vertical portionis substantially cylindrically shaped.

14. The device of embodiment 13, wherein the vertical portion comprisesa first semi-circle portion that is at least partially transparent, anda second semi-circle portion that is at least partially reflective.

15. The device of embodiment 14, wherein the second semi-circle portioncomprises a surface in thermal communication with a high-emissivitymaterial configured to facilitate radiation of heat away from the secondsemi-circle portion.

16. The device of embodiment 14, wherein the high-emissivity materialcomprises paint with an emissivity value greater than or equal to about0.9.

17. The device of any of embodiments 7-16, wherein the vertical portionis integrated with an internally reflective tube configured to channellight towards an interior space of the building.

18. The device of any of embodiments 7-17, wherein the height of thevertical portion is between 35 and 45 inches.

19. The device of any of embodiments 7-18, wherein the width of thecollector base aperture is between 20 and 25 inches.

20. An at least partially transparent light-collecting device fordirecting daylight into a building interior, the device comprising:

-   -   a top cover portion;    -   a base aperture having a width and configured to be disposed        adjacent to an opening of a building;    -   a substantially vertical portion having a height, the vertical        portion extending between the top portion and the base aperture        and configured to receive daylight when installed on a building;        and    -   a reflector associated with the vertical portion, the reflector        configured to reflect at least a portion of daylight received by        the vertical portion towards the opening;    -   wherein the vertical portion is associated with a prismatic        element configured to turn the portion of daylight received by        the vertical portion towards the opening; and    -   wherein the height of the vertical portion is greater than the        width of the opening of the building.

21. The device of embodiment 20, wherein the vertical portion has arectangular cross-sectional shape.

22. The device of any of embodiments 20-21, wherein the vertical portionhas a substantially elliptical cross-sectional shape.

23. The device of embodiment 22, wherein the vertical portion isconstructed out of a single sheet, wherein two ends of the sheet arejoined to form a single vertical seam.

24. The device of embodiment 22, wherein the vertical portion comprisesa plurality of curved sheets that are configured to be joined togetherto form a shape having a substantially elliptical cross section.

25. The device of any of embodiments 20-24, wherein the vertical portionhas a cross-sectional perimeter comprising one or more curved portionsand one or more straight portions.

26. A method of illuminating an interior of a building, the methodcomprising:

-   -   receiving daylight on a substantially vertical surface;    -   refracting the received daylight towards an opening in a        building using a prismatic element disposed within a        light-collecting device; and    -   reflecting the daylight towards the opening using a reflector.

27. The method of embodiment 26, wherein reflecting the daylightcomprising reflecting the daylight after it is refracted using theprismatic element.

28. A method of manufacturing an at least partially transparentlight-collecting device for directing daylight into a building interior,the method comprising:

-   -   providing a light collecting device configured to receive        daylight on a substantially vertical surface when installed on a        building having an opening;    -   disposing a prismatic element within the light collecting        device; and    -   disposing a reflector adjacent to a wall of the light collecting        device;    -   wherein the prismatic element is configured to turn at least a        portion of daylight received on the substantially vertical        surface towards the opening, and the reflector is configured to        reflect the portion of daylight towards the opening.

Discussion of the various embodiments disclosed herein has generallyfollowed the embodiments illustrated in the figures. However, it iscontemplated that the particular features, structures, orcharacteristics of any embodiments discussed herein can be combined inany suitable manner in one or more separate embodiments not expresslyillustrated or described. It is understood that the fixtures disclosedherein can be used in at least some systems and/or other lightinginstallations besides daylighting systems.

It should be appreciated that in the above description of embodiments,various features are sometimes grouped together in a single embodiment,figure, or description thereof for the purpose of streamlining thedisclosure and aiding in the understanding of one or more of the variousinventive aspects. This method of disclosure, however, is not to beinterpreted as reflecting an intention that any claim require morefeatures than are expressly recited in that claim. Moreover, anycomponents, features, or steps illustrated and/or described in aparticular embodiment herein can be applied to or used with any otherembodiment(s). Thus, it is intended that the scope of the inventionsherein disclosed should not be limited by the particular embodimentsdescribed above, but should be determined only by a fair reading of theclaims that follow.

What is claimed is:
 1. An at least partially transparentlight-collecting device configured to direct natural visible lightthrough a collector base aperture and into an interior of a buildingwhen the light-collecting device is installed on a roof of the building,the device comprising: a top cover portion; a substantially verticalsidewall portion configured to support the top cover portion above anupper end of the substantially vertical sidewall portion and to define acollector base aperture at a lower end of the substantially verticalsidewall portion, wherein the substantially vertical portion has aheight that extends between the top cover portion and the collector baseaperture, and wherein the substantially vertical portion is configuredto receive a substantial amount of daylight during midday hours, thedaylight comprising visible light and infrared light; a prismaticelement associated with the substantially vertical sidewall portion andconfigured to turn a substantial portion of visible light received bythe vertical portion towards the collector base aperture; and aninfrared control element connected to the light-collecting device,wherein the infrared control element is configured to direct asubstantial portion of the infrared light away from the collector baseaperture; wherein the light-collecting device is configured to bepositioned over an opening in a roof of a building and is configured todirect daylight into the opening in the roof when the light-collectingdevice is installed as part of a daylighting device installation.
 2. Thedevice of claim 1, wherein the infrared control element is configured toabsorb the infrared light and reradiate the infrared light away from aninterior of the light-collecting device.
 3. The device of claim 2,wherein the infrared control element comprises a material having highemissivity characteristics.
 4. The device of claim 3, wherein theinfrared control element comprises a material having an emissivity valuegreater than or equal to about 0.90.
 5. The device of claim 1, whereinthe sidewall portion is configured to substantially transmit theinfrared light directed away from the collector base aperture.
 6. Thedevice of claim 1, wherein the infrared control element is at leastpartially secured to the sidewall portion by an adhesive configured toabsorb infrared light incident on a surface of the infrared controlelement.
 7. The device of claim 1, wherein the infrared control elementcomprises a material painted on a surface of the sidewall configured toabsorb infrared light incident on a surface of the infrared controlelement.
 8. The device of claim 1, wherein the top cover portion issubstantially flat.
 9. The device of claim 1, wherein the top coverportion comprises a dome-shaped surface.
 10. The device of claim 1,wherein the vertical portion comprises a plurality ofvertically-arranged segments, including an upper segment and a lowersegment.
 11. The device of claim 10, wherein the upper and lowersegments are each approximately 5 to 30 inches in height.
 12. The deviceof claim 10, wherein the upper and lower segments are each of uniformheight.
 13. The device of claim 1, wherein the infrared control elementcomprises an optical element that has a luminous reflectance greaterthan or equal to about 0.95 with respect to CIE Illuminant D65 andtransmits a substantial portion of infrared light.
 14. The device ofclaim 1, wherein the vertical portion is curved.
 15. The device of claim14, wherein the infrared control element is curved and nestinglydisposed along an interior surface of the vertical portion.
 16. Thedevice of claim 14, wherein the vertical portion comprises a firstsemi-circle portion that is substantially luminously transparent, and asecond semi-circle portion that is substantially luminously reflective.17. The device of claim 16, wherein the second semi-circle portion isconfigured to absorb a substantial portion of infrared light incident ona surface of the second semi-circle portion.
 18. The device of claim 16,wherein the second semi-circle portion comprises a surface insubstantial thermal communication with a high-emissivity materialconfigured to facilitate radiation of thermal energy away from thedevice.
 19. The device of claim 18, wherein the high-emissivity materialhas an emissivity value greater than or equal to about 0.9, and whereinthe high-emissivity material comprises anodized metal, a coating, paint,or a combination of high-emissivity materials.
 20. A method ofilluminating an interior of a building using a daylighting systemincluding a light-collecting device mounted on the building, the methodcomprising: receiving daylight on a substantially vertical transparentsurface of the light-collecting device, wherein the daylight comprisesvisible light and infrared light; turning a substantial portion of thevisible light towards an opening in the building using a reflectorconnected to the light-collecting device; and transmitting or radiatinga substantial portion of the infrared light of the daylight away fromthe opening in the building.
 21. The method of claim 20, whereintransmitting or radiating the infrared light comprises absorbing theinfrared light and reradiating the infrared light away from the openingin the building.
 22. The method of claim 20, wherein transmitting orradiating the infrared light comprises radiating the infrared lightusing a high emissivity material disposed on an outside surface of thelight-collecting device.
 23. A method of manufacturing an at leastpartially transparent light-collecting device for directing naturalvisible light into a building interior, the method comprising: disposinga prismatic element within a light collecting device configured toreceive daylight on a substantially vertical transparent surface whenthe device is installed on a building having a daylighting opening,wherein the daylight comprises visible light and infrared light; andconnecting an infrared control element to the light collecting deviceand positioning the infrared control element such that the infraredcontrol element directs a substantial portion of the infrared light awayfrom the daylighting opening when the device is installed on thebuilding; wherein the prismatic element is configured to turn asubstantial portion of the visible light received on the substantiallyvertical surface towards the daylighting opening when the device isinstalled on the building; and wherein the infrared control element isconfigured to substantially transmit or absorb the infrared light. 24.An at least partially transparent light-collecting device configured todirect natural visible light through a collector base aperture and intoan interior of a building when the light-collecting device is installedon a roof of the building, the device comprising: a top cover portion; asubstantially vertical sidewall portion configured to support the topcover portion above an upper end of the substantially vertical sidewallportion and to define a collector base aperture at a lower end of thesubstantially vertical sidewall portion, wherein the substantiallyvertical portion has a height that extends between the top cover portionand the collector base aperture, and wherein the substantially verticalportion is configured to receive a substantial amount of daylight duringmidday hours, wherein the daylight comprises visible light and infraredlight; a prismatic element associated with the substantially verticalsidewall portion and configured to turn a substantial portion of thevisible light received by the vertical portion towards the collectorbase aperture; and a reflector associated with the substantiallyvertical sidewall portion configured to reflect a substantial portion ofthe visible light towards the collector base aperture and configured toabsorb or transmit a substantial portion of the infrared light; whereinthe light-collecting device is configured to be positioned over anopening in a roof of a building and is configured to direct the visiblelight into the opening in the roof when the light-collecting device isinstalled as part of a daylighting device installation.
 25. The deviceof claim 24, wherein the reflector is configured to absorb the infraredlight and radiate the infrared light away from the collector baseaperture.
 26. The device of claim 25, wherein the reflector comprises amaterial having high emissivity characteristics.
 27. The device of claim26, wherein the reflector comprises a material having an emissivityvalue of greater than or equal to about 0.90.
 28. The device of claim24, wherein the reflector is at least partially secured to the sidewallportion by an adhesive configured to absorb infrared light incident on asurface of the reflector.
 29. The device of claim 24, wherein thereflector is at least partially transparent with respect to infraredlight.
 30. The device of claim 24, wherein the vertical portion issubstantially cylindrically shaped.
 31. A daylighting system comprisingan internally reflective tube configured to direct light between thelight-collecting device of claim 24 and a diffuser.
 32. A method ofilluminating an interior of a building, the method comprising: receivingdaylight on a substantially vertical surface; turning the daylighttowards an opening in a building using a prismatic film disposed withina light-collecting device; reflecting a portion of visible light of thedaylight towards the opening using a reflector; and transmitting orradiating a portion of infrared light of the daylight out of thelight-collecting device.